Colorado is a state in the Mountain West subregion of the Western United States. It encompasses most of the Southern Rocky Mountains, as well as the northeastern portion of the Colorado Plateau and the western edge of the Great Plains. Colorado is the eighth most extensive and 21st most populous U.S. state. The 2020 United States Census enumerated the population of Colorado at 5,773,714, an increase of 14.80% since the 2010 United States Census.

The region has been inhabited by Native Americans for more than 13,000 years, with the Linden Meier Site containing artifacts dating from approximately 9200 BC to 1000 BC; the eastern edge of the Rocky Mountains was a major migration route for early peoples who spread throughout the Americas. “Colorado” is the Spanish adjective meaning “ruddy”, the color of red sandstone. The Territory of Colorado was organized on February 28, 1861, and on August 1, 1876, U.S. President Ulysses S. Grant signed Proclamation 230 admitting Colorado to the Union as the 38th state. Colorado is nicknamed the “Centennial State” because it became a state one century after the signing of the United States Declaration of Independence.

Colorado is bordered by Wyoming to the north, Nebraska to the northeast, Kansas to the east, Oklahoma to the southeast, New Mexico to the south, Utah to the west, and touches Arizona to the southwest at the Four Corners. Colorado is noted for its vivid landscape of mountains, forests, high plains, mesas, canyons, plateaus, rivers, and desert lands. Colorado is one of the Mountain States and is a part of the western and southwestern United States.

Denver is the capital and most populous city in Colorado. Residents of the state are known as Coloradans, although the antiquated “Coloradoan” is occasionally used. Colorado is a comparatively wealthy state, ranking eighth in household income in 2016, and 11th in per capita income in 2010. It also ranks highly in the nation’s standard of living index. Major parts of the economy include government and defense, mining, agriculture, tourism, and increasingly other kinds of manufacturing. With increasing temperatures and decreasing water availability, Colorado’s agriculture, forestry, and tourism economies are expected to be heavily affected by climate change.

Climate change in Colorado encompasses the effects of climate change, attributed to man-made increases in atmospheric carbon dioxide, in the U.S. state of Colorado.

The Denver Post has reported that individuals living in southeastern Colorado are more vulnerable to potential health effects from climate change than residents in other parts of the state”. The United States Environmental Protection Agency has more broadly reported:

CLIMATE CHANGE

“Colorado’s climate is changing. Most of the state has warmed one or two degrees (F) in the last century. Throughout the western United States, heat waves are becoming more common, snow is melting earlier in spring, and less water flows through the Colorado River. Rising temperatures and recent droughts in the region have killed many trees by drying out soils, increasing the risk of forest fires, or enabling outbreaks of forest insects. In the coming decades, the changing climate is likely to decrease water availability and agricultural yields in Colorado, and further increase the risk of wildfires”.

Records

The highest official ambient air temperature ever recorded in Colorado was 115 °F (46.1 °C) on July 20, 2019, at John Martin Dam. The lowest official air temperature was −61 °F (−51.7 °C) on February 1, 1985, at Maybell.