Climate Of France

The climate of France is the statistical distribution of conditions in the Earth's atmosphere over the national territory, based on the averages and variability of relevant quantities over a given period, the standard reference period defined by the World Meteorological Organization being 30 years. Climate characterization is based on annual and monthly statistical measurements of local atmospheric data: temperature, atmospheric pressure, precipitation, sunshine, humidity, wind speed. Recurrence and exceptional events are also taken into account.

Located between latitudes 41° 19' N and 51° 04'N, metropolitan France is currently in the temperate zone, characterized by warm summers and moderately cold winters. This classification distinguishes between oceanic (cool summers, mild winters, high precipitation), continental (hot summers, cold winters, low precipitation), Mediterranean (hot, dry summers, mild winters, autumn precipitation), mountain (colder and wetter than the surrounding plains) and altered oceanic (a transition zone between oceanic and mountain climates and semi-continental climate). Extreme temperatures recorded in mainland France are 46.0 °C in Vérargues on 28 June 2019 and −36.7 °C in Mouthe on 13 January 1968.

The climates of France's overseas territories are many and varied, depending on their position on the globe, ranging from the cold oceanic type for the subantarctic islands, to the tropical maritime type for the French West Indies, the equatorial type for French Guiana and the polar maritime type for Saint-Pierre-et-Miquelon. French Polynesia, which extends over 20 degrees of latitude, is divided into 5 types.

These climates have varied greatly in the past, with warm periods (optimums) and cold periods (ice ages). Paleoclimates, which date back to geological times, have been marked by alternating ice ages (around 80,000 years) and warm periods (around 20,000 years) at intervals of around 100,000 years. The last Ice Age was a period of global cooling, or glaciation, which marked the end of the Pleistocene on the entire planet. It began 115,000 years ago and ended 11,700 years ago, when the Holocene, the current interglacial period, began. The latter is characterized by the Roman climatic optimum (−300 to +200), the Medieval climatic optimum (900–1300) and the Little Ice Age (1300–1860). The contemporary period (1860 to the present) is marked by the end of the Alpine Little Ice Age (1860-1900-1910), followed by the onset of global warming.

The IPCC's sixth assessment report confirms with certainty the anthropization origin of the global warming already observed. Temperatures in mainland France today are 1.66 °C higher than those measured between 1900 and 1930, with 1.63 °C attributable solely to human activity. Analysis of more precise temperature data between 2010 and 2019 shows that, over this short period, France is warming by 0.1 °C every 3 years. To meet the two objectives of the Paris climate agreement (warming well below 2 °C and preferably limited to 1.5 °C), a sharp and immediate reduction in CO2 emissions is essential, until we reach carbon neutrality, the only way to halt global warming. Reducing emissions of other greenhouse gases, particularly methane, is also relevant. To meet this objective, France, through its climate policy, is deploying various mitigation and adaptation strategies, with specific targets such as reducing greenhouse gas emissions by 40% between 1990 and 2030 (20% in 2019) or reducing final energy consumption by 50% in 2050 compared with the 2012 baseline, with an intermediate target of 20% in 2030.

Notion of climate

The notion of climate has evolved considerably, and it's now easier to define what the "climate system" is, i.e. all the very different components that make up the atmosphere, the oceans, the continental surface, and all their physical, chemical and biological interactions. The word "climate" thus goes beyond the usual strictly atmospheric definition to designate the characteristics of the climate system in a given place, characteristics established over a period, often 30 years, known as the Climate Norm. The parameters used to describe a region's climate are many and varied, from temperature, wind and air humidity to soil water content, river conditions, atmospheric composition and ocean salinity. They are most often analyzed in terms of annual, monthly or seasonal averages. But characterizing climate also means describing rarer and more irregular events, such as violent storms or persistent drought.

France is a transcontinental sovereign state whose metropolitan territory extends across Western Europe, and whose overseas territories stretch across the Indian, Atlantic and Pacific oceans, as well as Antarctica and South America. It is thus characterized by a wide variety of climates, which have also been highly variable over time.

Paleoclimates

Milanković cycles

Life appeared on Earth between 3.8 and 3.5 billion years ago, in the form of the first cells. It was the first living organisms capable of recovering carbon from atmospheric CO2 dissolved in water and progressively enriching the atmosphere with oxygen (photosynthesis) that set in motion the dynamic cycle of water and climate. The first hominids appeared around 4 million years ago. Ice core records provide a good understanding of the climate over the last million years. It is marked by alternating ice ages (around 80,000 years) and warm periods (around 20,000 years) with a periodicity of around 100,000 years. Since the appearance of man, the average temperature at the Earth's surface has been relatively constant, varying by only a few degrees from an average of around 15 °C.

The regular alternation of warm and cold periods can be explained by astronomy. In 1924, Serbian geophysicist Milutin Milanković demonstrated that three independent parameters characterize the Earth's orbit around the sun and modulate the amount of solar energy according to the seasons: eccentricity, obliquity, the inclination of the Earth's axis of rotation on itself in relation to the plane of rotation around the sun (currently close to 23°) and climatic precession, a term defining variations in the Earth's axis of rotation. Each of these parameters varies over time with independent periods, and their conjunction makes the construction, or disappearance, of icecaps in the Northern Hemisphere more or less favorable, and these icecaps play a decisive role in climate. In France, the South-East basin, considered part of the Alpine domain, stands out from other French geological basins for the very great thickness of its sedimentary layer. Alternating marl and limestone deposits are particularly well exposed in the Vocontian Basin, where Lower Cretaceous formations are mostly in the form of alternating limestone banks and marl interbanks. These alternating sedimentary successions perfectly reflect the interlocking Milanković cycles, providing one of the best proofs of astroclimatic control of sedimentation.

Last Ice Age (−115,000 to −11,700 years ago)

Last Ice Age (−115,000 to −19,000 years ago)

The Last Ice Age is a period of global cooling, or glaciation, that marks the end of the Pleistocene on the entire planet. It began 115,000 years ago and ended 11,700 years ago, when the Holocene began.

Abrupt changes of millennial cyclicity punctuated this last glacial period and had a strong impact on terrestrial and marine ecosystems, as well as on atmospheric composition and temperature. Periods characterized by rising water temperatures in the North Atlantic, Greenland and greenhouse gas concentrations were contemporary with the development of forest in Europe below 50°N, and alternated with cold periods of steppe vegetation. During the changes observed around 40,000 years before present, Neanderthal man disappeared and modern man colonized Europe.

These changes, known as the Dansgaard-Oeschger cycles after their discoverers, have given rise to some forty very rapid climatic pulsations. These phases are associated with variations in North Atlantic surface water temperature and changes in climate on the European continent. These pulses lasted for several millennia, and the transition from a cold episode (stage) to a temperate episode (interstage) seems to have been very rapid, on the order of a few decades, sometimes less! Some of these cold episodes were accompanied by a massive influx of icebergs into the Bay of Biscay from the ice cap covering Canada. These iceberg break-ups, known as Heinrich events, were brutal: each would have lasted on the order of a century, or even a few millennia. Studies of Bay of Biscay sediments have shown that each Heinrich event is synchronous with the rapid development (< 100 years) of a "Central European-type" grass steppe at the expense of pine forest.

The glacial maximum was reached around 21,000 years ago. One of the consequences of this cooling was a marine regression (a general drop in sea level) of around 120 meters at its maximum, and the establishment of a periglacial climate in Europe, North Asia and North America, leading to profound changes in flora and fauna. At the time of this glacial maximum, the Arctic ice cap covered northern Europe, the glaciers of the Alps descended as far as Lyon, and those of the Pyrenees as far as Arudy (Pyrénées-Atlantiques). Sea level was around 120 m below present, and the shoreline was pushed ~50 km offshore. In southern Aquitaine, deglaciation of the high Pyrenean mountains must have ended around 15,000 years ago. During the last glacial episode, the Landes was a vast sandy expanse dotted with 'fields of small crescent-shaped dunes of metric height. Beyond the Garonne to the east and the Adour to the south, finer particles (loess) carried by storms to higher altitudes were deposited to form accumulations on the relief, where steppe vegetation then developed.

Tardiglacial (−19,000 to −11,700 years ago)

The Tardiglacial is the period between the Last Glacial Maximum, which ended around 19,000 years ago, and the beginning of the Holocene, 11,700 years ago, during which there was an irregular rise in temperatures, interspersed with relapses. The beginning of the Tardiglacial period in Europe was marked by the disappearance from our latitudes of certain "archaic" animal species (mammoths, woolly rhinoceroses, cave bears). Reindeer and horses ''( Equus caballus gallicus''), sometimes combined with Bovinae (bison or aurochs), became the dominant species of the early Interstadial period, judging by the hunting records of human societies.

The Alleröd (13,900 to 12,900 years ago) is characterized by an increase in tree cover. In the Paris Basin and in Belgium, pollen analyses enable us to distinguish two phases in this episode: the first is characterized by the establishment of an open birch forest (afforestation rate of around 45%); the second, which may be separated by a slight retreat in tree cover, sees the expansion of an open pine-dominated forest. Arctic species are partly replaced by woodland species: aurochs and horses – occasionally present – are joined by deer, roe deer, wild boar, elk and beaver.

Cave paintings can also provide clues to the climate, but these must be interpreted with care. Plants are rare in cavern art, but the animals depicted can help us to understand the climate outside, even if the species depicted on the cave walls represent only a selection. The compositions do not constitute a photograph of the external landscape. The presence of a saiga antelope on a wall in Rouffignac (Dordogne) betrays cold, dry steppe conditions. The fact that there is only one reindeer and no mammoth depicted at Lascaux may indicate milder temperatures (or perhaps the artists weren't interested in these animals).

The question is: did the artists reproduce images of animals that actually lived in their territory? As Jean-Loïc Le Quellec points out, elephants can be found sculpted on Romanesque churches, even though this pachyderm did not really frequent our forests. The large bulls in the Rotonde de Lascaux are well known, but certain chronological attributions of the cave mean that its decoration began at a time when aurochs (lovers of wooded environments) were not very present in the immediate environment. According to François Djindjian, mammoths had disappeared from the Périgord by the Middle Magdalenian, and were only found further north, in the Loire and Saône basins and in the Paris Basin. Yet Rouffignac was decorated at this time! He therefore proposes that the artists drew them from memory, having gone to contemplate them in a sort of safari avant la lettre. However, new research indicates that mammoths still existed on the banks of the Vézère at this time. Moreover, as Florian Berrouet points out: "The addition of numerous details indicating seasonality or the extreme naturalistic rigor of the artists (anal flap, eye contour, triangular lower lip) and making each animal unique, endowed with a real personality, forces us to believe that man must have rubbed shoulders with, or even observed, these mammoths for a long time." During colder periods, the big beasts migrated in herds southwards, towards hospitable territories. It is perhaps the memory of such a vision that the Magdalenians of Rouffignac immortalized on stone.
File:Prehistoric Sites and Decorated Caves of the Vézère Valley-108437.jpg, Bulls on the Lascaux rotunda.
File:Lascaux painting.jpg, Aurochs in the Lascaux cave. Lascaux 2.
File:Grotte de Rouff mammut.jpg, Mammoth and ibex engraved in the Rouffignac cave.
At the end of the period ( Dryas III), a very severe cold snap led to a return of arctic species, a further retreat of forest and an extension of steppe and tundra landscapes. It ends abruptly with a rapid rise in temperatures.

Climates of the current interglacial period

Temperature changes over the Holocene

The current Holocene interglacial period began some twelve thousand years ago, at the end of the Last Glacial Period (known as the Würm for its Alpine component). In the mountains of Europe, small glaciers also formed in the Vosges, Black Forest, Massif Central, Carpathians, Pyrenees, Apennines, Balkans and Sierra Nevada, as well as in northwest Spain, Crete and Corsica. The deglaciation that preceded it lasted around 10,000 years and resulted in a rise in temperature of around 4 °C and a rise in sea level of around 130 metres.

A study tracing mean annual surface air temperatures across Europe over the last 12,000 years was published in 2003. It is based on quantitative climate reconstructions from over 500 pollen sites assimilated using an innovative four-dimensional gridding procedure. It appears that the Holocene climatic optimum was only observed in northern Europe, and therefore did not affect France. This warming was offset by a mid-Holocene cooling in southern Europe. Trends in mean annual temperatures for the whole of Europe suggest an almost linear increase in the heat budget up to 7800 BC, followed by stable conditions for the rest of the Holocene. This warming at the beginning of the Holocene, followed by an equilibrium, was mainly modulated by rising winter temperatures in the west, which have continued to rise at a progressively decreasing rate to the present day.

Southern Europe and the Mediterranean have experienced almost linear warming since around 8,000 BC. This warming preceded the onset of any major human impact and continued at the same rate until the end of the Holocene, a period of anthropogenic significance. This suggests not only that the Mediterranean climate has an essentially natural origin, but also that the pollen-climate calibration method has remained independent of human impact on vegetation.

The study divides Europe into six parts, delimited in latitude by the 45°N and 55°N parallels and in longitude by the 15°E meridian. France, crossed by the 45°N parallel ( Bordeaux latitude), is represented by two parts: the part north of 45°N is in Central-Western Europe, and the part to the south is in Southwestern Europe. The graphs representing temperature variations in mainland France over the Holocene, reconstructed from pollen data, are shown below.
File:Tempé Holocène Europe CW.svg
File:Tempé Holocène Europe SW.svg

Climatic and cultural sequences throughout the Holocene

In southern France (below latitude 45°N), the climate changed around 8,000 BC. From this date onwards, we can distinguish a phase known as Boreo-Atlantic, which ends with a cold episode, which appears to be worldwide, centered on 6,250 BC. This phase seems to have been marked by a relatively uncertain climate, or at least one of great contrasts. Then, for around half a millennium, we witness the return of an Atlantic ensemble – towards which the sequence preceding this episode was already tending. This is defined by high, very regular rainfall from Spain and North Africa to the Balkans. In addition, average temperatures (and particularly average summer temperatures, the most favorable for vegetation) are said to have been 1.5° to 2 °C higher than in the 1970–1980 period. They may even have exceeded them by 2° to 2.5 °C during what are known as climatic optimum sequences (the first of which occurred around 5700 BC).

Comparing these major climatic sequences with the major cultural sequences may reveal a link between certain sequences. The following table shows such a timeline for Haute-Provence. While the cultural sequences are identical throughout France, the years separating them vary from region to region. This is particularly true of the Neolithic period, when the first groups settled in Provence, Languedoc and Corsica around 5500 BC, but only reached certain other parts of France several hundred years later.

Roman climatic optimum (−300 to +200)

The rise of the Roman Empire and viticulture in Gaul

The period between 300 B.C. and A.D. 200 witnessed the development and rise to power of the Roman Empire. This prosperous period is considered socially stable. It corresponds precisely to the period of the Roman Climatic Optimum (RCO), when summers are warm and rather humid. These climatic conditions favored the development of agriculture, as well as the establishment of ornamental gardens. This situation is linked to greater solar activity, linked to the activity of ocean currents, and low volcanic activity. The OCR would therefore have been particularly beneficial to the strong development of viticulture, which expanded in the three Gauls during the 1st. century, reaching as far as southern England. Generally speaking, since agriculture was the Roman Empire's primary source of wealth, it is now clearer that this climatic change was a powerful driving force behind economic development until the 1st. century.

Lyon's development in flood zones

The settlement and development of the city of Lyon in a flood zone benefited from a favorable climatic context linked to the Little Roman Optimum, corresponding to a period of moderate hydrology. A reconstruction of the hydrosedimentary variability of the Rhône at Lyon from 1000 BC to 2000 AD shows the approximate fluctuation of solid and liquid flows over the period. In particular, these curves describe an oscillation during the period between the end of the 1st century BC and the 1st century AD. This was a short period of climatic oscillation, with several episodes of flooding characterized by greater intensity and frequency than in earlier and later periods. The main floods have been dated to the reigns of Augustus, Tiberius and Claudius, between 27 BC and 54 AD. Another climatic oscillation can be seen in the early Middle Ages

This ancient hydrosedimentary crisis within the Roman Petit Optimum can be identified in other areas of Gallia Narbonensis. For example, during the same period, the Saint-Ferréol branch of the Rhône, in the delta, continued to advance. Elsewhere, the port of Narbonne (''Narbo Martius'') experienced accelerated silting in the 1st century. In Lyon, archaeological digs have shown that the urban society of the city's riverside adapted to this crisis through a series of developments designed to occupy the peninsula between the Rhône and Saône rivers.

Late Antiquity: climatic disasters and the fall of the Roman Empire

The impact of climatic degradation during Late antiquity on the end of the Roman Empire in the West has long been widely discussed in scientific literature. It has been seen as the cause of the great barbarian invasions, of a drop in cereal yields causing famine, of a change in land use, with a conversion of arable land to pasture in Western Europe, and so on. It has also been suggested that the development of rye cultivation in Gaul in late Antiquity was an adaptation of agriculture to the colder climate, which would be an example of resilience. This period of climatic change would thus have affected agricultural production and played a role in historical upheavals, in particular the fall of the Western Roman Empire. But climate was certainly not the sole cause of the fall of the Roman Empire. By the end of the Empire, Roman society was certainly more vulnerable or more exposed to environmental conditions. North American historian Kyle Harper insists on the role of pandemics in the Empire's weakening, due in particular to several periods of plague.

Medieval climatic optimum (900–1300)

The medieval Little Optimum Period (POM) took place in Western Europe between 900 and 1250–1300 AD, with seasons that were slightly milder or warmer, and perhaps drier, than those of the following period. The Little Medieval Optimum may have seen average temperatures of 0.5 °C higher than those of the Little Ice Age that followed, which was itself 0.7 to 0.8 °C lower than those of the end of the 20th century.

Climate zones in mainland France

Worldwide classifications

Latitudinal distribution

Climatologists have drawn up a number of classifications to reflect the diversity of situations on the planet. Overall, they delineate three main zones according to latitude (cold, temperate and hot climates). France is in the temperate zone, characterized by hot summers and moderately cold winters. This classification distinguishes between oceanic (cool summers, mild winters, high precipitation), continental (hot summers, cold winters, low precipitation) and Mediterranean (hot, dry summers, mild winters, autumn precipitation) climates. Within these three climatic zones, a variety of nuances emerge, depending on parameters such as altitude (mountain climate, colder and wetter than in the surrounding plains).

Köppen classification

The Köppen classification is a climate classification based on precipitation and temperature. It was invented in the 1920s by botanist Wladimir Peter Köppen, who combined the world vegetation map published in 1866 by Hermann Griesbach and the division of climate into five zones by de Candolle. A climate is thus identified by a two- or three-letter code. This is the most common climatic classification, in the version presented by Rudolf Geiger in 1961. The Köppen-Geiger map remains a reference today, thanks to its frequent updates, in the fields of hydrology, geography, agriculture, biology and climatology through its research into the evolution of climates.

A large part of mainland France lies in the oceanic domain (Cfb), while the plains and hills bordering the Mediterranean basin have a climate designated by Csa.

Eco-climatic classifications

Climate parameters can be used to predict the type of vegetation in an area, just as examining flora can deduce the climate. The UNDP and the WWF use these bioclimatic criteria to define ecozones. This type of classification describes biomes and not strictly climates, with the climate being deduced from the biome. In green, temperate deciduous and mixed forests; in brown, Mediterranean forests, woodlands and scrub
File:Koppen-Geiger_Map_v2_FRA_1991–2020.svg, Köppen-Geiger classification of France based on 1991-2020 data.
File:Biomes of the world.svg, WWF classification, differentiating 14 terrestrial biomes (two for France).

National typologies

8 types of climate (Joly et al. – 2010)

A 2010 study by Daniel Joly, Thierry Brossard, Hervé Cardot, Jean Cavailhes, Mohamed Hilal and Pierre Wavresky classified metropolitan France's climates into eight major types. Based on station measurements of precipitation and temperature provided by Météo-France, a set of 14 variables incorporating a 30-year time series (1971–2000) was defined to characterize climates and their distinctive modes of variation. An original method known as local interpolation was used to reconstitute the continuous spatial fields of the variables in question, and to express them in the form of information layers manageable by GIS. The result is 8 types of climate

* Type 1 (blue): ''mountain climates'' include all areas where mountain and/or semi-continental influences predominate, with a high number of days and a high accumulation of precipitation, an average temperature below 9.4 °C and, correlatively, more than 25 days with a minimum temperature below −5 °C and fewer than 4 with a maximum above 30 °C.
* Type 2 (light-blue): s''emi-continental climate and climate of the mountain margins'' include the mountain peripheries and extend over vast areas where temperatures are less cold than in the mountains (although, at equal altitude, they are colder than anywhere else), precipitation is slightly lower and less frequent, but climatic variability over the 1971–2000 normal is just as high.
* Type 3 (turquoise): ''The degraded oceanic climate of the central and northern plains'' remains oceanic, but with some fine gradations. Temperatures are intermediate (around 11 °C annual average, between 8 and 14 days with temperatures below −5 °C). Precipitation is low (less than 700 mm annual total), especially in summer, but rainfall averages 12 days in January and 8 in July, which are average values for France as a whole.
* Type 4 (pale green): ''The altered oceanic climate'' represents a transition between the frank oceanic (type 5) and the degraded oceanic (type 3). The average annual temperature is fairly high (12.5 °C), with a low number of cold days (between 4 and 8 per year) and a high number of hot days (between 15 and 23 per year). The annual temperature range (July–January) is close to the minimum, and interannual variability is average. Precipitation, average yearly (800–900 mm), falls mainly in winter, while summer is fairly dry.
* Type 5 (dark green): ''Oceanic climate.'' Temperatures are average and very homothermic: annual amplitude (less than 13 °C difference between July and January), number of cold days (less than 4) and hot days (less than 4) and interannual variability are minimal. Precipitation is abundant every year (just over 1,000 mm) and frequent in winter (over 13 days in January). Summer is also rainy (8–9 days in July), but rainfall totals are low.
* Type 6 (vivid green): ''Altered Mediterranean climate.'' The average annual temperature is high, with a small number of cold days and hot days ranging from 15 to 23/year. Interannual variability in July temperatures is minimal: summer is repeatedly hot from one year to the next. Annual precipitation is average (800–950 mm), but not evenly distributed.
* Type 7 (orange): ''The climate of the Southwest Basin'' is characterized by high mean annual temperatures (above 13 °C) and a high number (> 23) of warm days, while days with frost below −5 °C are rare. The annual thermal amplitude is high (15 to 16 °C) and the interannual variability of winter and summer temperatures is low. Precipitation, which is not very abundant (less than 800 mm) in winter, is slightly more abundant in summer. It is more frequent in winter (9-11 days) than in summer (less than 6 days).
* Type 8 (yellow): ''The frank Mediterranean climate.'' The climatic characteristics are very clear-cut, more so than in any of the previous seven climates. Annual temperatures are high, with rare cold days and frequent hot days. The inter-annual amplitude is high (over 17 °C between July and January), while these characteristics are very stable from one year to the next. The very high ratio of autumn to summer precipitation (> 6) is the main characteristic of this climate. Cumulative annual precipitation is low, with an arid summer but a fairly well-watered winter despite a low number of rainy days.

5 types of climate (Météo-France – 2022)

Climate characterization has also been the subject of various types of representation, notably umbrothermal diagrams (climatograms, climograms or climate maps). These graphical representations show precipitation and temperature for each month of the year. The etymology of the word ombrothermique is in fact linked to the Greek ombros (storm rain) and thermique (relating to heat, temperature). The temperatures and precipitation used in these diagrams correspond to average monthly data for a given location, recorded over thirty years. This type of visual representation makes it possible to compare the temperature and precipitation of different climates in relation to each other. For example, the French territory is made up of several climates: oceanic (Brest), altered oceanic (Cambrai), semi-continental (Lons-le-Saunier), Mediterranean (Marseille) and mountain (Chamonix Mont-Blanc).

The map of these five major climate types in mainland France published by Météo-France in 2022, together with the characterization of these climates and the representative umbrothermal diagrams, are as follows

* Type 1. ''The oceanic climate'' is characterized by mild temperatures and relatively abundant rainfall (due to disturbances from the Atlantic), distributed throughout the year, with a slight maximum from October to February. The city of Brest is representative of this climate.

File:FR-Brest-Guipavas-Diagramme climatique 1971-2000.svg, Climate normals 1971-2000
File:FR-Brest-Guipavas-Diagramme climatique 1981-2010.svg, Climate normal 1981-2010
File:FR-Brest-Guipavas-Diagramme climatique 1991-2020.svg, Climate normals 1991-2020

* Type 2. ''The altered oceanic climate'' is a transition zone between the oceanic climate and the mountain and semi-continental climates. Temperature differences between winter and summer increase with distance from the sea. Rainfall is lower than at the seaside, except in the vicinity of relief. The towns of Orléans and Cambrai are typical of this climate.

File:FR-Orleans-Bricy-Diagramme climatique 1971-2000.svg, Climate normals 1971-2020
File:FR-Orleans-Bricy-Diagramme climatique 1981-2010.svg, Climate normal 1981-2020
File:FR-Orleans-Bricy-Diagramme climatique 1991-2020.svg, Climate normals 1991-2020


File:FR-Cambrai-Diagramme climatique 1971-2000.svg, Climate normals 1971-2020
File:FR-Cambrai-Diagramme climatique 1981-2010.svg, Climate normal 1981-2020
File:FR-Cambrai-Diagramme climatique 1991-2020.svg, Climate normals 1991-2020
Type 3. ''Semi-continental climate.'' Summers are hot and winters harsh, with many days of snow or frost. Annual rainfall is relatively high, except in Alsace, which benefits from the protective effect of the Vosges mountains (föhn effect). Rainfall is heaviest in summer, often with thunderstorms. The city of Besançon is representative of this climate

File:FR-Besancon-Diagramme climatique 1971-2000.svg, Climate normals 1971-2000
File:FR-Besancon-Diagramme climatique 1981-2010.svg, Climate normal 1981-2010
File:FR-Besancon-Diagramme climatique 1991-2020.svg, Climate normals 1991-2020
Type 4. ''Mountain climate.'' Temperature decreases rapidly with altitude. There is minimal cloud cover in winter and maximum in summer. Winds and precipitation vary considerably according to location. The town of Bourg-Saint-Maurice (altitude: 865 m) is representative of this climate.

File:FR-Bourg-Saint-Maurice-Diagramme climatique 1971-2000.svg, Climate normals 1971-2000
File:FR-Bourg-Saint-Maurice-Diagramme climatique 1981-2010.svg, Climate normal 1981-2010
File:FR-Bourg-Saint-Maurice-Diagramme climatique 1991-2020.svg, Climate normals 1991-2020

Type 5. ''The Mediterranean climate'' is characterized by mild winters and hot summers, plenty of sunshine and frequent strong winds. There are few rainy days, irregularly distributed over the year. Dry winters and summers are followed by very wet springs and autumns, often in the form of thunderstorms (40% of the annual total in 3 months). In just a few hours, this precipitation can bring 4 times more water than the monthly average to a given location, particularly near the relief (Mediterranean episode). The city of Marseille is representative of this climate.

File:FR-Marseille-Diagramme climatique 1971-2000.svg, Climate normal 1971-2020
File:FR-Marseille-Diagramme climatique 1981-2010.svg, Climate normal 1981-2020
File:FR-Marseille-Diagramme climatique 1991-2020.svg, Climate normals 1991-2020

29 climate regions (Météo-France – 2020)

In 2020, Météo-France is also publishing a map showing a breakdown into 29 climatic regions, taking into account the many factors that can influence climate on a regional scale, such as latitude, altitude, distance from the sea or major mountain ranges, etc.

Microclimates

Overseas France

Overseas France, with its widely scattered territories, has a wide variety of climates.

Saint-Pierre and Miquelon

Saint-Pierre and Miquelon has a cold, humid oceanic climate. According to Köppen's classification, Saint-Pierre and Miquelon is in category Dfb (humid continental climate) / Dfc (subarctic climate with no dry season).

To the east of the large North American continental landmass, the climate is strongly influenced by it. Prevailing westerly quadrant winds originating on the continent come into contact with the ocean, often resulting in significant temperature contrasts. In winter, these winds are very cold and come into contact with milder oceanic air masses, creating or activating vigorous disturbances that generate intense snowfalls and sharp temperature drops. In summer, the flow is slightly different: warm and sometimes humid continental air masses from the Gulf of Mexico, upwelling via the American continent, come into contact with cold ocean waters (cold polar downwelling, also known as the "Labrador Current"), often resulting in thick, tenacious fog. The air is stabilized by the cold water, and rainfall is lower at this time of year.

This is a semi-continental climate, with fairly cold winters (average February temperature of −3.5 °C in Saint Pierre), though milder than on the American mainland, and very cool summers (15.5 °C in Saint Pierre in August, cooler than in mainland France at the same latitude) due to the presence of cold oceanic water. At the heart of this clash of air masses with very different characteristics, rainfall is abundant (1,312 mm per year in Saint-Pierre), with a winter maximum.

French West Indies (Guadeloupe, Saint-Martin, Saint-Barthélemy, Martinique), Reunion Island, Indian Ocean islands (Îles Éparses), Mayotte, New Caledonia, French Polynesia, Wallis and Futuna.

These islands, whose latitude extends a little beyond the Tropics (Rapa 27° 37 S) and less than ten degrees towards the equator (Hiva-Oa 9° 49 S), are located in the flow of the trade winds that blow regularly at these latitudes. These disturbances are moderate during the dry season, which corresponds to the winter at higher latitudes, and much more frequent and abundant during the summer and especially autumn periods of the year, as a result of the higher ocean temperatures at this time and the growing instability due to the proximity of the ITCZ (Inter-Tropical Convergence Zone), which rises in latitude in the summer hemisphere. There is a clear contrast between the "windward" slope exposed to the trade winds, which receives between 1,500 and 2,500 mm of rain annually (up to 4,634 mm annually at Plaine des Palmistes in La Réunion, at an altitude of 1,032 m), and the "leeward" slope (980 mm annually at Koumac in New Caledonia), which is much drier and even arid in places. The months with the least rainfall have between 30 and 90 mm (the dry season is relative), while the months with the most rainfall have between 200 and 400 mm.

In addition to the upsurge in rainfall in late summer/autumn, these islands are exposed to devastating tropical cyclones at this time of year, both in terms of the amount of rain dumped in a few hours and the stormy winds associated with them.

Due to the oceanic environment and low latitude, annual averages are high (Ile des Pins 22.5 °C, Saint Denis 24 °C, Le Lamentin 26.2 °C) and temperature differences are not very marked in these regions. Differences from one day to the next and from one season to the next are not very marked. The annual amplitude increases slightly as you move away from the equator, ranging from 1.9 °C in Hiva-Oa