PORTLAND, Ore. (KOIN) — The unofficial start to summer began Monday and Portland feels the heat Tuesday afternoon.

Increasing sunshine will help warm afternoon highs nearly 10-degrees warmer than average Tuesday. Willamette Valley temperatures will easily climb into the low- to mid-80s Tuesday afternoon. This is just the start to western Oregon and southwest Washington’s latest warming and drying trend.

Portland area temperatures will continue to warm as a ridge of high pressure builds over the western half of the country. Wednesday’s the expected peak of the heat where Portland could feel some of the warmest temperatures of the year so far, with highs expected in the mid to upper 80s.

Wildfire sparks in Central Oregon Sunday afternoon near Clarno

Staying hydrated, taking breaks indoor or in the shade while wearing light-colored loose-fitting clothes should be practiced during the hottest moments of the day. Heat illness and stroke is possible for those who are sensitive to the high heat.

The heat will be brief as an onshore flow pattern helps to cool us back into the 70s by Thursday. There’s a slim chance for a sprinkle or two, but little to no rain accumulation is expected.

Hottest temps of the year possible in Portland this week

Portland’s warmer and drier weather pattern through the end of May 2025

Another warming trend is expected heading into the weekend. Another strong ridge of high pressure could push temperatures close to 90 again on Friday or Saturday. Disagreements in the timing and peak of the heat is still unclear. However, clarity will come as the weekend approaches.

Stay with KOIN 6 Weather for all the latest details.