Coolest day of the week possible Thursday around Portland

PORTLAND, Ore. (KOIN) -- The coolest day of the week arrives in Portland on Thursday after a record-breaking stretch of excessive heat.

Despite feeling slightly cooler Thursday, Portland temperatures will remain above average by nearly 10 degrees. The summer-like heat isn't expected to fade at least through the next week. Highs in the upper 80s and low 90s will take much of the Willamette Valley into the middle of next week.

The warmer-than-average conditions along with the lack of rainfall will keep Oregon and Washington's wildfire threat elevated. Abnormally dry conditions are working their way back into the Pacific Northwest. As relative humidity values, above-average temperatures, and the lack of rainfall increase so too does the fire threat.

Several fires burning in the Pacific Northwest will keep skies over eastern Oregon and Washington hazy. Northwesterly winds will keep Portland area skies free of poor air quality and the worst of the haze.

Sunny skies and warmer-than-normal temperatures are expected by the weekend. Some afternoon highs will push toward the mid-90s this weekend, but will struggle to succeed around Portland.

The lack of rainfall will likely send the Portland, Vancouver metro area into nearly two weeks without measurable rainfall. The last measurable rain accumulation was only one one-hundredths of an inch of rain back on June 27.