Seattle Climate — Average Highs, Lows & Rainfall by Month
Seattle has a temperate climate with four distinct seasons. Daytime temperatures average 25°C / 77°F in August, the warmest month, and drop to 8°C / 46°F in January, the coldest. Overnight lows in January average 2°C / 36°F. Seattle receives about 1129 mm of rain a year across roughly 142 wet days, with December the wettest month.
Averages for 2021–2025 · Open-Meteo Historical Weather API (ERA5 reanalysis) · Updated 2026-10-05
Monthly averages in Seattle
Average daytime high, overnight low and rainfall for each month of the year.
| Month | Avg high | Avg low | Rainfall | Wet days |
|---|---|---|---|---|
| January | 8°C / 46°F | 3°C / 37°F | 171 mm | 16 |
| February | 8°C / 46°F | 2°C / 36°F | 109 mm | 14 |
| March | 11°C / 52°F | 4°C / 39°F | 98 mm | 15 |
| April | 13°C / 56°F | 6°C / 42°F | 73 mm | 14 |
| May | 17°C / 63°F | 9°C / 48°F | 56 mm | 11 |
| June | 21°C / 70°F | 12°C / 54°F | 48 mm | 7 |
| July | 25°C / 78°F | 15°C / 58°F | 7 mm | 1 |
| August | 25°C / 77°F | 15°C / 60°F | 31 mm | 6 |
| September | 21°C / 70°F | 13°C / 55°F | 50 mm | 7 |
| October | 15°C / 60°F | 9°C / 49°F | 111 mm | 14 |
| November | 10°C / 51°F | 6°C / 42°F | 172 mm | 17 |
| December | 8°C / 47°F | 4°C / 39°F | 201 mm | 20 |
Best time to visit Seattle
July, August, June offer the most comfortable weather in Seattle: mild daytime temperatures with the year's lowest rainfall — July averages 25°C (78°F); August averages 25°C (77°F); June averages 21°C (70°F).
Seattle climate FAQ
- What is the hottest month in Seattle?
- August is the hottest month in Seattle, with average daytime highs of 25°C / 77°F and overnight lows of 15°C / 60°F (averages for 2021–2025).
- What is the coldest month in Seattle?
- January is the coldest month in Seattle, with average highs of 8°C / 46°F and lows of 3°C / 37°F.
- How much rain does Seattle get a year?
- Seattle receives about 1129 mm of rainfall a year, spread over roughly 142 wet days. December is the wettest month (201 mm on average) and July the driest (7 mm).
- When is the best time to visit Seattle?
- July, August, June are the most comfortable months in Seattle: mild daytime temperatures with the least rainfall of the year.
Want today's conditions instead of averages?
See live weather in Seattle →Source: Open-Meteo Historical Weather API (ERA5 reanalysis), Open-Meteo. Averages are daily means across 2021–2025 and are rounded for display — for a live forecast see the Seattle weather page.