Fox News Weather Center

Dramatic Cooldown, Storms to Help Ease Northwest Fire Situation

After enduring the hottest days of the year so far in Seattle and Portland, a storm system will bring cooler air and rainfall to the Pacific Northwest during the middle of the week.

The high temperature reached 96 in Seattle and 99 in Portland on Monday, nearly 20 degrees above normal for both cities.

The heat was not limited to areas along the Interstate 5 corridor as Spokane, Washington, had a high of 98, while Boise, Idaho, reached 102. Both cities were only 2 degrees below the hottest temperatures of the summer.

The recent heat will quickly be erased as temperatures tumble by 10-15 degrees on Tuesday and fall further on Wednesday as highs climb into only the mid-70s for both cities.

Along with the cooler air, an increase in moisture will fuel scattered showers and thunderstorms through Wednesday.

This storm will shift eastward on Thursday continuing the threat of showers and thunderstorms across the interior Northwest, while drier air builds into areas west of the Cascades.

More typical mid-August temperatures will prevail across the Northwest from Thursday into the weekend.

This change to cooler, wetter weather will be mainly beneficial for firefighters battling the many wildfires across the region.

More than 30 large fires are still uncontained from northern California into Oregon, Washington, Idaho and Montana.

An increase in relative humidity due to both lower temperatures and higher dew points will aid containment efforts across the region over the next several days. Each day through Thursday will yield better conditions for fire containment.

One concern, however, is that any thunderstorms could still spark new blazes as lightning will be widespread across the region. Also, any wind gusts from thunderstorms can spread current fires and also lead to dangerous wind shifts for those fighting the fires.