New Climate Normals: Seattle Area Is Warmer, Wetter

SEATTLE — Over the last decade, Western Washington's climate has become both warmer and wetter, according to a new report from the National Oceanic and Atmospheric Administration.

The federal agency updates its 30-year "climate normals" report every decade, and the latest includes changes analyzed from 2010 to 2020. The National Weather Service's Seattle outpost looked at the findings for key takeaways locally and walked through some of the highlights.

For Western Washington, meteorologists found higher temperatures and wetter years almost across the board, with drier days in late spring and early summer. NWS Seattle said most stations were wetter under the new normals, except for Bellingham, and all were warmer.

Sea-Tac Airport and Bellingham showed the most significant temperature changes, showing a full degree warmer in both high and low temperatures in annual averages. In Seattle, every month got warmer, with May increasing the most at 1.5 degrees.

For precipitation, Seattle saw its annual rainfall average increase to 39.34 inches, up from 37.49 inches. The National Weather Service said a notable increase in days with one or more inches of rain was likely a contributing factor to the overall trend.

Seattle is not alone in its warming trend, as seen in the data across most U.S. states. In Alaska, one climate expert noted that, under the new normals, Fairbanks is now considered to be in a "warm summer continental" climate rather than a "sub-Arctic" climate.

Much of the nation has also seen more annual precipitation, while many Western states have become significantly drier.

Learn more about the new climate normals on the NOAA website.