Spring is getting warmer in Washington State

Spring (March-April-May) temperatures in Washington have increased at an average rate of 0.10 F per decade since 1930, and 0.48 F per decade since 1950.[[National Climactic Data Center, “Washington Climate Summary,” The trend values given in this entry are up-to-date as of September 2009.]] The more recent trend is greater because of cooling that occurred in the 1940s, and because of rapid warming in the decades since. The warming is consistent with broader patterns of average temperature increase in the American West that have been attributed, at least in part, to human-induced climate change.