Late September Climate Outlook
What’s Next for the Pacific Northwest?
Slight chances of above normal precipitation and temperatures for October 2025.
The Climate Prediction Center’s monthly outlook for October 2025 looks to be warm across the interior western United States with a slight chance (33-40%) of warmer than normal temperatures extending up into Washington State. As weak La Niña conditions continue to develop in the Tropical Pacific, odds have tilted in favor of above normal precipitation across the state as well. There is currently a 40-50% chance of wetter than normal conditions across the majority of the state with a 33-40% chance across the far southern OR/WA border through October 2025.
The seasonal forecast for October through December also reflects developing La Niña pattern with odds tilted toward wetter than normal conditions statewide. The highest chances (40-50%) exist across the far eastern third of the state. Temperature outlook shows equal chances of above, below, or near-normal conditions for this fall and early winter period.
La Niña watch issued for Winter 2025-2026
Although ENSO neutral conditions are still present, a La Niña watch remains in place for the upcoming winter. Sea surface temperatures in the Tropical Pacific and convection patterns over the western Pacific indicate a gradual shift toward La Niña conditions is largely unfolding as expected. La Niña conditions would likely be fairly weak and brief, ending by late winter or early spring. A return to neutral conditions is most likely thereafter.