Unseasonably hot air to engulf Portland and Vancouver metro
A powerful ridge of high pressure is settling over the Pacific Northwest, creating what may be the hottest stretch of weather so far this year for the Portland and Vancouver metro areas. As of this week, temperatures are forecast to climb well above seasonal norms, with the potential to reach the upper 80s (31–32 °C) and even hit 90 °F (32.2 °C) in parts of the Willamette Valley.
Temperature timeline and patterns
The heat will build quickly, with lower 80s (27–28 °C) expected as early as Tuesday, ramping up to upper 80s (31–32 °C) or potentially 90 °F (32.2 °C) by Wednesday. This surge aligns with the peak intensity of the high-pressure system, which will drive sunny skies and dry conditions across the region.
By Thursday, a temporary weakening of the ridge will allow for a brief cooldown, with highs dropping into the mid-70s (23–24 °C)—still warm, but noticeably cooler than the peak. However, another ridge is forecast to rebuild quickly, pushing temps back into the 80s and possibly low 90s by the weekend.
May heat: Anomaly or expectation?
Late May in Portland typically features average highs in the lower 70s (21–22 °C). This week’s forecasted warmth will land 10 to 15 degrees above normal, making it rare but not unprecedented. On average, Portland’s first 90 °F (32.2 °C) day doesn’t arrive until June 18th, underlining just how early and extreme this heat wave could be.
Stay aware of local conditions as forecast models evolve throughout the week. The KOIN 6 Weather Team will continue monitoring the changes, especially as the second wave of warmth approaches for the weekend.
