Portland is starting Monday near 40 degrees under mostly clear skies, but the chilly morning will give way to sunshine and a high near 66. Winds should stay light, making for a crisp but comfortable Columbus Day across the city. The forecast stays dry through most of the week before cooler, foggier conditions return this weekend.
Frost Risk Lingers Outside Portland
A frost advisory remains in effect through 8 a.m. Monday for many interior valleys and lower-elevation areas around the region; Portland’s urban core should stay a few degrees warmer than outlying spots, according to the National Weather Service. Gardeners in colder areas may still want to cover sensitive plants before sunrise.
Clear Skies Continue Through Wednesday
Monday night will be mostly clear, with temperatures dipping to around 44 degrees. Tuesday should be mostly sunny with a high near 65, followed by another mostly sunny day Wednesday and a high near 70. Winds will remain light throughout the stretch.
Thursday And Friday Bring The Warmest Weather
The warmest days of the week arrive Thursday and Friday, when sunny skies push afternoon highs to around 76 degrees, with overnight lows settling in the low to mid-50s, as reported by the National Weather Service. It is a brief stretch of patio-friendly weather before the forecast gets more unsettled.
A Recent October High In Context
Preliminary National Weather Service climatological data list a high of 82°F in Portland on Oct. 4, 2026, before this forecast period. That single reading provides recent context, but it does not establish how often mid-70s highs occur or how unusual they are in the city’s historical climate.
Weekend Brings Fog And Slight Rain Chances
Dry weather is expected through the week, with precipitation chances returning toward the end of the weekend. Saturday brings patchy fog. Saturday’s high should reach about 68, while Sunday will be partly sunny after morning fog with a high near 66. Neither day currently looks like a washout, but early risers may want an extra layer and a little patience on the roads.
