Climate in Seattle — Annual Weather Overview
Seattle has a oceanic climate — mild temperatures year-round with regular rainfall. The hottest month is August (average high 24.9°C) and the coolest is December (7.6°C). The seasons are strongly defined — a 17.3°C swing between August highs and December lows. Annual rainfall totals around 1159mm. January is the wettest month at 216.0mm, while July averages just 8.0mm. Average daily sunshine is 7.8 hours.
**Spring (March, April, May):** average highs 13.6°C, 221mm rain. **Summer (June, July, August):** average highs 23.5°C, 88mm rain. **Autumn (September, October, November):** average highs 15.6°C, 345mm rain. **Winter (December, January, February):** average highs 8.0°C, 505mm rain.
Seattle — Monthly Temperatures
Seattle — Monthly Rainfall
✅ Best months to visit
All year
ℹ️ No months to avoid
Weather in Seattle stays reasonable all year.
Seattle weather by month
| Month | High | Low | Rain | Sun/day | Rainy days | Rating |
|---|---|---|---|---|---|---|
| January | 8.3°C | 3.3°C | 216.0mm | 3.8h | 20 | 8/10 |
| February | 8.0°C | 2.4°C | 104.8mm | 5.2h | 14 | 9/10 |
| March | 10.2°C | 3.4°C | 82.6mm | 7.1h | 14 | 10/10 |
| April | 13.3°C | 5.2°C | 73.7mm | 9.3h | 13 | 10/10 |
| May | 17.4°C | 9.3°C | 64.7mm | 9.8h | 11 | 10/10 |
| June | 20.9°C | 12.3°C | 58.6mm | 11.1h | 9 | 10/10 |
| July | 24.6°C | 14.6°C | 8.0mm | 12.6h | 2 | 10/10 |
| August | 24.9°C | 15.2°C | 21.5mm | 11.6h | 5 | 10/10 |
| September | 21.3°C | 13.1°C | 66.1mm | 9.3h | 8 | 10/10 |
| October | 15.4°C | 9.4°C | 104.4mm | 6.3h | 13 | 9/10 |
| November | 10.0°C | 4.9°C | 174.8mm | 4.6h | 18 | 9/10 |
| December | 7.6°C | 3.1°C | 184.1mm | 3.2h | 20 | 9/10 |
For the full verdict on when to go, see the best time to visit Seattle and the Seattle rainy season guide. Seasonal breakdowns: spring, summer, autumn and winter.
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Frequently Asked Questions
What type of climate does Seattle have?
Seattle has a oceanic climate — mild temperatures year-round with regular rainfall. Average highs range from 7.6°C in December to 24.9°C in August.
What is the hottest month in Seattle?
August is the hottest month in Seattle, with average highs of 24.9°C and lows of 15.2°C.
What is the coldest month in Seattle?
December is the coolest month, with average highs of 7.6°C and lows of 2.4°C.
What is the wettest month in Seattle?
January is the wettest month, averaging 216.0mm of rainfall over around 20 rainy days.
When is rainy season in Seattle?
Rainy season in Seattle runs October to February, when rainfall is significantly higher than the rest of the year. Full rainy season guide →
How much rain does Seattle get per year?
Seattle receives around 1159mm of rain per year. The driest month is July (8.0mm).
When is the best time to visit Seattle?
The best time to visit Seattle is All year. See the full month-by-month guide →
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Trip essentials for Seattle
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More Seattle travel essentials
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Climate data sourced from Open-Meteo (open source, open data licence). Monthly averages calculated from 2020–2023 historical data. Weather can be unpredictable — always check a live forecast before travelling.