Trends in Temperature and Precipitation for the United States
Long-term U.S. temperatures since 1895 show generally cooler conditions in the late 1800s, followed by warming through the 1930s, and then cooling into the 1970s. Since the 1970s, temperatures have warmed steadily through 2007. While both 2008 and 2009 were cooler, they were still warmer than the temperatures seen in the cool period between 1950 and 1980.
U.S. precipitation was generally drier between 1895 and 1970 than after 1970. However, there are considerable year to year and decade to decade variations. Data from these two graphs are available as an Excel spreadsheet.
Annual Temperature for the U.S. (click to enlarge) |
Annual Precipitation for the U.S. (click to enlarge) |
Notes
The data source for both the temperature and precipitation data are the National Climatic Data Center.
An 11-year, moving average was included to smooth out some of the year-to-year variability in the records.