Utah's Dixie is the nickname for primarily the populated, lower elevation area of south-central Washington County in southwestern Utah. Its climate is very mild when compared to the rest of Utah, and typical of the Mojave Desert, in which it lies. Situated below the Black Ridge and the Hurricane Cliffs, in the northeastern edge of the Mojave Desert. It was part of Mexico and settled by the Southern Paiutes. It was first inhabited by Mormon settlers in 1854, as part of Brigham Young's efforts to establish an Indian Mission in the region. The settlers began growing cotton and other temperate cash crops during the later 1850s on land that had fed the Paiute. The Paiute population was decimated as a result of starvation and disease. The largest community in the region, St. George, was founded in 1861, when Brigham Young selected 300 families to take over the area and grow cotton, grapes, and other crops.:3 The region was nicknamed Dixie by 1860.
Andrew Larson’s  text on the history of the name “Dixie” in Utah states that in 1857, the first President of the Washington Stake was Robert Dockery Covington, a slave overseer and slave owner from North Carolina and Mississippi. Larson states:
Already the settled area of the Virgin Valley was being called Utah’s “Dixie.” The fact that cotton would grow there, as well as tobacco and other semi-tropical plants such as the South produced made it easy for the name to stick. The fact that the settlers at Washington were bona fide Southerners who were steeped in the lore of cotton culture—many of them, at least—clinched the title. Dixie it became, and Dixie it remained. ... The name “Dixie” is one of those distinctive things about this part of Utah ... It is a proud title— Andrew Larson, I Was Called to “Dixie” (p. 185) [Emphasis in original]
Whatever the real origins of the term, the Cotton Mission didn't work out as well as Young had hoped – yields in the test fields were not as high as expected, and economic viability of growing cotton was never achieved, although a cotton mill was built and used for a few years in the town of Washington.
The largest city in the area is St. George, with a population of nearly 150,000 in the metropolitan area.
South-central Washington County, (the greater St. George area) has become a retirement and recreational haven due to its pleasant winter climate, many golf courses and red sandstone landscape. In the winter (December and January), temperatures average in the mid to upper 50s F. during the day with nighttime temperatures averaging just below freezing. Heavy snowfall is rare, however slight accumulation typically occurs once or twice during these cooler months, usually completely melting in a day or two. The humidity is extremely low (usually below 25% in the summer), and the area receives an average of about 8 to 10 inches of rainfall annually. Summers are long and hot with high temperatures exceeding 100 °F. (40 °C.) from about late May through September, with the exception of the cooling rains of the southwest Monsoon. The record high temperature was recorded in the area near the Arizona line at 117 °F. (47 °C.). Utah's Dixie is one of the fastest-growing regions in the United States, being located in the Sunbelt. St. George and its suburbs of Ivins, Santa Clara, and Washington, along with Hurricane, are the largest and fastest-growing cities within the region.