One Sunny Sunday Before Smoky 90-Degree Blast Bakes Portland

Portland is starting Sunday, August 23, under cloudy skies near 64 degrees, but the gray is expected to break as afternoon temperatures reach about 78. The bigger swing comes Monday, when sunshine, areas of smoke and a high near 90 will turn up the heat across the city.

Clouds Clear Before A Dry Afternoon

Sunday morning stays mostly cloudy, with temperatures rising through the 60s before skies become partly sunny and then mostly sunny by afternoon. Rain is unlikely, with only a 4% chance for the day, and winds should stay light as they shift from the southwest toward the north.

Sunday night will be mostly clear and cooler, with a low around 58 degrees. A weak front is expected to move through the region overnight, but the city’s forecast remains largely dry, according to the National Weather Service in Portland.

Monday Brings Heat And Smoke

Monday brings the sharpest change of the week: sunny skies, areas of smoke after 9 a.m. and a high near 90 degrees. North-northwest winds will stay light, and no rain is expected.

Tuesday will remain sunny but a little cooler, with a high near 87. Overnight lows in the upper 50s and low 60s should offer some relief after the afternoon heat fades.

Seasonable Weather Returns Midweek

By Wednesday, temperatures drop back to about 79 degrees, followed by highs near 77 Thursday through Saturday. The rest of the week looks mostly sunny or partly cloudy, with precipitation chances staying at 2% or lower through Saturday.

People spending time outside Monday may want to plan strenuous activity for the morning or evening, especially if smoke becomes noticeable. Portland has no land-based watches, warnings or advisories in this forecast, though small-craft advisories are posted for nearby coastal waters and the Columbia River bar, where winds could approach 30 mph Monday.