Questions have been raised about whether poor siting practices that have existed in recent years at some in situ weather-observing stations are causing a bias in U.S. temperature change analysis. This potential bias was examined using homogeneity-adjusted maximum, minimum, and mean temperature data from five stations in eastern Colorado—two with good current siting and three with poor current siting. No siting-induced bias was found in the homogeneity-adjusted data. Furthermore, the results indicate that homogeneity-adjusted time series from the stations with poor current siting represent the temperature variability and change in the region as a whole quite well because they are very similar to the time series from stations with excellent siting.
NOAA's National Climatic Data Center, Asheville, North Carolina