But even during more typical times of July and August the region produces widely varying climates, depending on the location's distance from the Pacific Ocean.
The image to the right of Washington and Oregon was captured at midday on August 18, 2011, by the MODIS instrument orbiting aboard NASA’s terra satellite.
It reveals a landscape of contrast, with temperate rain forests along the coastal strip and parched deserts in the interior.
Those deserts are robbed of moisture due to a “rain shadow” created by the crest of the Cascades.
Pacific cold fronts expend almost all of their moisture in rainfall as they pass over the coastal high terrain.
That leaves residents in the heart and eastern portions of Washington and Oregon relying on rivers, irrigation, wells and the odd shower that makes it into the naturally barren landscape.
The numerous snow-capped mountains of the northern Cascades and Washington’s Olympic Peninsula are evidence of the wet and mild conditions that have prevailed since the normal end of the Pacific storm season.
Maritime low cloudiness and fog can also be seen hugging that peninsula and the southwestern shores of Vancouver Island.
Just southeast of Boise is smoke from a 10,000-acre brush fire near the community of Glenns Ferry. The Magic Valley blazes were contained just hours before the image was captured.
Image: NASA MODIS Rapid Response System