Seattle Weather in September
20.7°C high · 10.6°C low · 45 mm rain · 6.2h sun
Yes — Sep is one of the best months to visit Seattle, with mild weather and 6.2h of daily sunshine.
September at a glance
| Metric | Value |
|---|---|
| Average high | 20.7°C |
| Average low | 10.6°C |
| Rainfall | 45 mm |
| Sunshine | 6.2 hours/day |
| Daylight | 12.3 hours |
What to pack in September
Pack a jacket and layers for Seattle in September.
Seattle weather by month
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Frequently asked questions
What is the weather in Seattle in September?
Highs of 20.7°C and lows of 10.6°C, with about 45 mm of rain and 6.2 hours of sunshine per day.
Is September a good time to visit Seattle?
Yes — Sep is one of the best months to visit Seattle, with mild weather and 6.2h of daily sunshine.
What to do in Seattle · Best time to visit Seattle
Climate data: Open-Meteo Historical (ERA5), 1991–2020. CC BY 4.0.