Lāhainā Noon, also known as a zero shadow day, is a semi-annual tropical solar phenomenon when the

Sun The Sun is the star at the centre of the Solar System. It is a massive, nearly perfect sphere of hot plasma, heated to incandescence by nuclear fusion reactions in its core, radiating the energy from its surface mainly as visible light a ...

culminates at the

zenith The zenith (, ) is the imaginary point on the celestial sphere directly "above" a particular location. "Above" means in the vertical direction (Vertical and horizontal, plumb line) opposite to the gravity direction at that location (nadir). The z ...

solar noon Noon (also known as noontime or midday) is 12 o'clock in the daytime. It is written as 12 noon, 12:00 m. (for '' meridiem'', literally 12:00 midday), 12 p.m. (for ''post meridiem'', literally "after midday"), 12 pm, or 12:00 (using a 24-hour clo ...

, passing directly overhead. As a result, the sun's rays will fall exactly vertical relative to an object on the ground and cast no observable

shadow A shadow is a dark area on a surface where light from a light source is blocked by an object. In contrast, shade occupies the three-dimensional volume behind an object with light in front of it. The cross-section of a shadow is a two-dimensio ...

. When this occurs at a given location, the location is Earth's

subsolar point The subsolar point on a planet or a moon is the point at which its Sun is perceived to be directly overhead (at the zenith); that is, where the Sun's rays strike the planet exactly perpendicular to its surface. The subsolar point occurs at the ...

. A zero shadow day occurs twice a year for locations in the

tropics The tropics are the regions of Earth surrounding the equator, where the sun may shine directly overhead. This contrasts with the temperate or polar regions of Earth, where the Sun can never be directly overhead. This is because of Earth's ax ...

(between the

Tropic of Cancer The Tropic of Cancer, also known as the Northern Tropic, is the Earth's northernmost circle of latitude where the Sun can be seen directly overhead. This occurs on the June solstice, when the Northern Hemisphere is tilted toward the Sun ...

at approximate latitude 23.4° N and the

Tropic of Capricorn The Tropic of Capricorn (or the Southern Tropic) is the circle of latitude that contains the subsolar point at the December (or southern) solstice. It is thus the southernmost latitude where the Sun can be seen directly overhead. It also reach ...

at approximately 23.4° S) when the Sun's

declination In astronomy, declination (abbreviated dec; symbol ''δ'') is one of the two angles that locate a point on the celestial sphere in the equatorial coordinate system, the other being hour angle. The declination angle is measured north (positive) or ...

becomes equal to the

latitude In geography, latitude is a geographic coordinate system, geographic coordinate that specifies the north-south position of a point on the surface of the Earth or another celestial body. Latitude is given as an angle that ranges from −90° at t ...

of the location, so that the date varies by location. The term "Lāhainā Noon" was initiated by the

Bishop Museum The Bernice Pauahi Bishop Museum, designated the Hawaii State Museum of Natural and Cultural History, is a museum of history and science in the historic Kalihi district of Honolulu, Hawaii, Honolulu on the Hawaiian island of Oʻahu. Founded in 1 ...

Hawaii Hawaii ( ; ) is an island U.S. state, state of the United States, in the Pacific Ocean about southwest of the U.S. mainland. One of the two Non-contiguous United States, non-contiguous U.S. states (along with Alaska), it is the only sta ...

Details

The

travels through the

is the only US state in the tropics and thus the only one to experience Lāhainā Noon. In 2022 and 2023, the phenomenon occurred in

Honolulu Honolulu ( ; ) is the List of capitals in the United States, capital and most populous city of the U.S. state of Hawaii, located in the Pacific Ocean. It is the county seat of the Consolidated city-county, consolidated City and County of Honol ...

on May 26 and July 16. Hawaii and other locations between the

and

receive the sun's direct rays as the apparent path of the sun passes overhead before and after the

summer solstice The summer solstice or estival solstice occurs when one of Earth's poles has its maximum tilt toward the Sun. It happens twice yearly, once in each hemisphere ( Northern and Southern). The summer solstice is the day with the longest peri ...

. Lāhainā Noon can occur anywhere from 12:16 to 12:43pm Hawaii–Aleutian Standard Time. At that moment objects that stand straight up (

flagpole A flagpole, flagmast, flagstaff, or staff is a pole designed to support a flag. If it is taller than can be easily reached to raise the flag, a cord is used, looping around a pulley at the top of the pole with the ends tied at the bottom. The fla ...

bollard A bollard is a sturdy, short, vertical post. The term originally referred to a post on a ship or quay used principally for mooring boats. In modern usage, it also refers to posts installed to control road traffic and posts designed to pre ...

telephone poles ''Telephone Poles'' is the second book of poetry written by American writer John Updike. Publication The collection was published by Alfred A. Knopf, Knopf in 1963. Reception In ''The New York Times'', critic X.J. Kennedy wrote, "Of younger ...

, etc.) cast no outward shadow. The most southerly points in Hawaii experience Lāhainā Noon on earlier and later dates than the northern parts. For example, in 2001

Hilo Hilo () is the largest settlement in and the county seat of Hawaii County, Hawaiʻi, United States, which encompasses the Island of Hawaiʻi, and is a census-designated place (CDP). The population was 44,186 according to the 2020 census. I ...

on the

Island of Hawaii Hawaii is the List of islands of the United States by area, largest island in the United States, located in the Hawaii, state of Hawaii, the southernmost state in the union. It is the southeasternmost of the Hawaiian Islands, a chain of volcani ...

encountered the overhead sun around May 18 and July 24,

Kahului Kahului () is an unincorporated community and a census-designated place (CDP) in Maui County in the U.S. state of Hawaii. It hosts the county's main airport ( Kahului Airport), a deep-draft harbor, light industrial areas, and commercial shoppi ...

Maui Maui (; Hawaiian language, Hawaiian: ) is the second largest island in the Hawaiian archipelago, at 727.2 square miles (1,883 km2). It is the List of islands of the United States by area, 17th-largest in the United States. Maui is one of ...

, on May 24 and July 18,

Oahu Oahu (, , sometimes written Oahu) is the third-largest and most populated island of the Hawaiian Islands and of the U.S. state of Hawaii. The state capital, Honolulu, is on Oahu's southeast coast. The island of Oahu and the uninhabited Northwe ...

, on May 26 and July 15 and Lihue,

Kauai Kauai (), anglicized as Kauai ( or ), is one of the main Hawaiian Islands. It has an area of 562.3 square miles (1,456.4 km2), making it the fourth-largest of the islands and the 21st-largest island in the United States. Kauai lies 73 m ...

, on May 31 and July 11. Between each pair of dates, the sun is slightly to the north at solar noon. Chosen in a contest sponsored by the

in the 1990s, Lāhainā Noon was the selected appellation because ''lā hainā'' (the old name for Lāhainā, Hawaii) means "cruel sun" in the

Hawaiian language Hawaiian (', ) is a critically endangered Polynesian language of the Austronesian language family, originating in and native to the Hawaiian Islands. It is the native language of the Hawaiian people. Hawaiian, along with English, is an offi ...

. The

ancient Hawaii Ancient Hawaii is the period of Hawaiian history preceding the establishment in 1795 of the Kingdom of Hawaii by Kamehameha the Great. Traditionally, researchers estimated the first settlement of the Hawaiian islands as having occurred sporad ...

an name for the event was ''kau ka lā i ka lolo'' which translates as "the sun rests on the brains."

Subsolar dates

In popular culture

The event is often covered by Hawaiian media. Activities are associated with the event. ''Sky Gate'', a unique sculpture in Honolulu created by artist and landscape architect

Isamu Noguchi was an American artist, furniture designer and Landscape architecture, landscape architect whose career spanned six decades from the 1920s. Known for his sculpture and public artworks, Noguchi also designed stage sets for various Martha Grah ...

, features a bendy, bumpy ring that has large changes in height around its circumference. Most of the year, it makes a curvy, twisted shadow on the ground, but during Lāhainā Noon, the height-changing ring casts a perfect circular shadow on the ground. There are often activities held by the City & County of Honolulu around the time of the event on the Frank Fasi Civic Grounds, where the sculpture is located. The phenomenon occurs in stories, including "Lāhainā Noon" by Eric Paul Shaffer (Leaping Dog, 2005), which won the Ka Palapala Po'okela book award for Excellence in "Aloha from beyond Hawaii".

Gallery

File:Shadows during Lahaina Noon (5767078745).jpg, Lāhainā Noon in

Downtown Honolulu Downtown Honolulu is the current historic, economic, and governmental center of Honolulu, the capital and largest city of the U.S. state of Hawaii. It is bounded by Nuuanu Stream to the west, Ward Avenue to the east, Vineyard Boulevard to the n ...

File:Sky Gate by Isamu Noguchi.jpg, ''Sky Gate'' by Isamu Noguchi

References

External links

Annual Astronomy Highlights link has current "Lahaina Noon" dates
updated by the Bernice P. Bishop Museum
Picture of "Lahaina Noon"
by the

Honolulu Star-Bulletin The ''Honolulu Star-Bulletin'' was a daily newspaper based in Honolulu, Hawaii, Honolulu, Hawaii, United States. At the time publication ceased on June 6, 2010, it was the second largest daily newspaper in the state of Hawaii (after the ''Honol ...

, note the street sign
Picture of "Lahaina Noon"
by the

Hawaii culture Sun Solar phenomena