Seattle Rainy Season Begins with Autumnal Equinox
Seattle Rainy Season Begins with Autumnal Equinox
US · Published Sep 23, 2026
As autumn begins in Seattle, the region transitions from its dry summer to the start of the rainy season. According to Emerald City Weather Blog, the rainy season officially kicks off on October 1, with daily rainfall averages exceeding 0.10 inches (2.54 mm) by October
The first week of October is typically marked by residents planning outdoor activities, such as pumpkin patch visits, around the few dry days in the forecast. By mid-October, temperatures drop significantly, with the last 80°F (26.7°C) day of the year expected around October

Impact & Risks

The shift to the rainy season will bring increased precipitation, which could lead to localized flooding in low-lying areas. Outdoor activities, such as pumpkin patch visits, may be affected by muddy conditions and wet weather, particularly in mid-October. Residents should also prepare for cooler temperatures, with highs dropping below 60°F (15.6°C) by mid-month. The onset of stormy weather in late October could bring wind alerts and potential disruptions, such as fallen leaves and debris on roads.

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