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 2 (1895 through 2010) and Canada's Adjusted Historical Canadian Climate Data (AHCCD) (through 2006).
These data sets have been adjusted for biases or inhomogeneities resulting from changes in the environment or operation
of individual observing sites (e.g., urbanization, station moves, and instrument and time of observation changes).
The map may also be used for analyzing snow water equivalent (SWE) totals (through 2009) for WA State only, which are recorded on the first day of each month (January, February, March, April, and May) from the SNOTEL (Snowpack Telemetry) network. This 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 available begins in 1930 with more stations 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 to graph the station's data.