Climate on the Colorado Plateau

The climate of the Colorado Plateau is highly variable from north to south and from low to high elevations.  In the north, the Colorado Plateau’s climate is closely tied to that of the Great Basin; summers are hot with infrequent afternoon thunderstorms that tend to focus mostly on higher elevation areas.  In the south, however, the Plateau has peak precipitations in the winter and again in the summer because of moisture derived from southern monsoonal weather patterns.  Spring and fall are generally the driest periods.

Storms Across the Colorado Plateau

Colorado Plateau Native Plant Program

Annual precipitation amounts are less than 10 inches at the mid and lower elevations, while areas above 8,000 feet receive over 20 inches of precipitation.  The few and highly scattered mountains that reach elevations near or more than 11,000 feet elevation can receive nearly 3 feet of precipitation.  

And, like precipitation, temperatures also vary considerably within the Colorado Plateau.  In the southern and lower elevations, temperatures range from the low 20’s (degrees Fahrenheit) in the winter to the lower and mid 90’s in the summer.   At mid and upper elevations, temperatures range from the low 60’s and 70’s in the summer, to the single digits and low teens in the winter.

Multi-decadal droughts cycles are linked to Pacific Decadal Oscillation (PDO), which is an index of sea surface temperatures in the northern Pacific.

Climate Change and the Colorado Plateau
Much research has been and is being done related to climate change in the Colorado Plateau and there are numerous sources of information on the subject.  Recent climate change models applied to the Colorado Plateau predict significant changes in the next 30-100 years.  Predictions include temperature increases of 3.0oC (5.4oF) by 2050 during May and June when drought stress is greatest, and by 4.5-5.0oC (8.1-9oF) by 2090.  Winter temperatures are estimated to increase on the order of 2.5oC (4.2oF) by 2050 and 3.0oC (5.4oF) by 2090.  Winter temperatures are likely to rise by similar amounts by 2050 and 4.0oC (7.2oF) by 2090.

By 2090, precipitation is predicted to decline by as much as 5 percent across the Colorado Plateau.  This reduction, while apparently small, is critical when looking at the already low amounts of precipitation most of the region experiences.  Any declines in precipitation are likely to increase drought stress in existing native plant communities resulting in a greater susceptibility of existing ecosystems to replacement by noxious and other invasive weedy species.

Colorado Plateau Research Station
The Nature Conservancy’s Canyonlands Research Center
Climate Change at Northern Arizona University
Western Regional Center of the National Institute for Climatic Change Research (NICCR)
CLIMAS: Climate Assessment for the Southwest
National Ecological Observatory Network – Southern Rockies-Colorado Plateau
Northern Arizona Universities, Land Use History of North America – Colorado Plateau, Climate

A Few Available Publications and Web Links on Climate History and Change 

Schwinning, S., J. Belnap, D. R. Bowling, and J. R. Ehleringer. 2008. Sensitivity of the Colorado Plateau to change: climate, ecosystems, and society. Ecology and Society 13(2): 28. [online] URL: http://www.ecologyandsociety.org/vol13/iss2/art28/ 

Millar, C.I. 2006. Climate Change; Confronting the Global Experiment. In: Proceedings of the Forest Vegetation Management Conference; Redding, CA January 2006. [online] URL: http://www.fs.fed.us/psw/publications/millar/pub_global_experiment.pdf