Observed Climate Records
Observations are the basis for understanding past climate variability, for modeling future climate, and for evaluating future climate scenarios. The earliest instrumental weather observations in the Intermountain West came from some of the early military forts built on the western frontier in the mid-1800s. The longest continuous records in the region date back to the 1870s, though relatively few records begin before 1900.
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| Annual precipitation, 1900-2012, observed at the COOP station in Fort Colliins, CO. From the 2014 Climate Change in Colorado Report. |
Today there are over 600 weather stations in Colorado, Utah, and Wyoming which report at least daily temperature and precipitation observations to the National Weather Service under the auspices of the Cooperative Observer (COOP) Network. Several hundred more stations report daily or hourly weather information as part of other networks, including SNOTEL, RAWS, and CoAgMet. It is important to note that these observing systems were generally not constructed and maintained with the goal of detecting long-term climate trends, with the exception of more recent efforts such as NOAA's Climate Reference Network (CRN). See the 2014 Climate Change in Colorado Report, Chapter 2 for a discussion of the issues surrounding the use of weather station records for climate trend analysis.
Observed Climate - Observing Networks and Station Data
COOP Stations - Western Regional Climate Center (WRCC)
SNOTEL - Natural Resources Conservation Service (NRCS)
RAWS - Western Regional Climate Center (WRCC)
CoAgMet - Colorado Climate Center (CCC)
Utah MAPS Climate Server (multiple networks) - Utah Climate Center (UCC)
Observed Climate - Gridded Data and other Value-Added Products
Westmap (PRISM gridded climate data) - PRISM Climate Group, Oregon State University
PRISM Data Server - Wyoming State Climate Office
Colorado Climate Trends - Colorado Climate Center (CCC)
University of Colorado Boulder 
