PORTLAND, Ore. (KOIN) -- After a weekend that saw record-setting triple-digit heat, we will begin a slow cooldown Monday. Day 4 of our late summer heatwave gripping the Portland metro and much of the Willamette Valley.

It is also another KOIN 6 Weather Alert day, as we continue to experience temperatures as much as 15 degrees above average for this time of the year.

Expect temperatures in the low to mid-90s Monday across the Portland metro area, with much cooler weather at the Oregon Coast where temperatures will stay in the mid-60s and lower 70s. • Air Advisory graphic for August 25, 2025 (KOIN)

We will also continue to see wildfire smoke, haze and ozone pollution from motor vehicles as the hot ridge of high pressure currently over us allows for very little wind to mix up the atmosph

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