UW News

September 15, 2018

Video: Dry and warm — summer 2018 conditions in Washington state


In August 2018, Karin Bumbaco, the assistant state climatologist for Washington and a research scientist at the University of Washington’s Joint Institute for the Study of the Atmosphere and Ocean, commented on the summer weather across the state.

“It’s definitely an unusual summer. We’ve been drier than our normally dry, and also temperatures have been warmer,” Bumbaco said.

Washington had its third-warmest summer — for the months of May, June, July and August — since 1895. The trend was less the result of heat waves than just a steady, overall warmth.

“While we haven’t had a really extremely hot days, say in the upper 90s in Western Washington, the baseline is so much warmer,” Bumbaco said. “We haven’t seen that many days of cool, cloudy skies that tend to make up a summer in Seattle, in particular.”

A healthy water supply locked in winter snow got derailed by unusual spring and summer weather.

“In the beginning of April, we had normal to above-normal snow throughout Washington state, and that’s really important for our water supply later in the spring and summer,” Bumbaco said. “But beginning in mid-April, temperatures warmed drastically. So that snowpack melted very rapidly — much faster than usual.”

Summer rainfall was only about 20 to 40 percent of normal for much of the state.

Washington map with orange and red

That hit some places harder than others, Bumbaco said.

“Places with reservoirs to hold that water, like Yakima, were able to store that and release it slowly,” she said, for use throughout the summer. But other regions of the state, especially those that rely on summer rain, were experiencing drought conditions by the end of August.

The September issue of the monthly newsletter that Bumbaco produces for the Office of the State Climatologist, based at the UW, summarizes the conditions across the state and shows how the 2018 season compared to previous summers on record.


For more information, contact Bumbaco at 206-543-3145 or kbumbaco@uw.edu.