Use the options below to analyze temperature and precipitation trends around the Northwest using high quality data from the United States Historical Climatology Network (USHCN)
version 18.104.22.16850123 (through 2014). This data set has been adjusted for biases and inhomogeneities resulting from changes in the environment or operation
of individual observing sites (e.g., urbanization, station moves, instrument upgrades, and time of observation changes). The procedure adjusts only the temperature data - the precipitation data are raw - so
please use more caution interpreting the trends in precipitation. More information on the USHCN data set can be found in Menne et al. (2009).
The map may also be used for analyzing snow water equivalent (SWE) totals (through 2014) for WA State only, which are recorded on the first day of each month (January, February, March, April, and May) from snow course locations and the SNOTEL (Snowpack Telemetry) network. The SNOTEL network collects snowpack and related climate data from automated stations throughout the mountain regions in the western U.S. and is maintained by the U.S. Dept. of Agriculture Natural Resources Conservation Service (NRCS). The earliest data (from manual snow course measurements) begins in 1930 and more stations are available in later time periods.
For temperature data, each circle on the map is scaled based on the station's temperature trend calculated per decade with red indicating increasing temperature and blue decreasing. Similarly, for precipitation and SWE data, each circle on the map is scaled based on the percent change over the selected period with red indicating decreasing values and blue increasing. Click the legend icon on the left side of the map for additional information.
Click on an individual circle for a time series graph of the selected station's data.