The two warmest days of the year so far are expected today and Thursday with highs reaching the upper 80s in Spokane with lower and middle 90s possible elsewhere.
Higher air pressure is causing the early summer warm up, and garden growing conditions that are nearly perfect for setting tomatoes, peppers and squashes.
But a low off the Pacific coast is threatening to bring thunderstorms by Thursday night.
Increasing clouds are likely on Thursday with highs of 89 in downtown Spokane and Coeur d’Alene.
Spokane has yet to reach 90 degrees.
National Weather Service forecasters said the cold front is more likely to bring gusty winds and temperatures in the lower to middle 70s by Friday.
Lows will dip to about 50 on Friday and Saturday nights after several nights in the middle and upper 50s.
The greatest risk of thunderstorms will be in north central Washington, the mountains of Northeast Washington and the mountains of southeast Washington and the central Idaho Panhandle.
Forecasters said they do not expect severe storms as the cold front passes Thursday night into Friday morning.
Warmer temperatures are likely over the weekend with sunny skies. Highs will be about 75 on Saturday before going to the low 80s on Sunday through Tuesday.
The Pend Oreille River below Albeni Falls Dam has been dropping steadily as the snow pack is depleted in the mountains. The river has been above flood stage for several weeks, but should return to its banks later this week when the dam reaches a flow of 100,000 cubic feet per second, forecasters said. The river was running at 103,000 cfs today.
At 7 a.m., it was 63 at Spokane International Airport, 60 at Felts Field, 59 in Coeur d’Alene and Deer Park and 63 in Pullman.