Seattle climate
Seattle is warmest in August, with average highs of 25 °C, and coldest in February, when nights average 1.8 °C. November is the wettest month (192 mm) and July the driest (25 mm). Figures are 1991–2020 climate normals.
Across a full year Seattle averages 1,296 mm of rain, 39 days above 25 °C and 33 days below freezing.
United States · 56 m elevation · population 780,995 · 1991–2020 normals
Temperature below 0 °C to above 30 °C Rain band height is that month’s share of the wettest month
- Warmest month August 25 °C
- Coldest month February 1.8 °C
- Driest month July 25 mm
- Wettest month November 192 mm
- Least cloud July 45 % cloud
- Hottest on record July 38 °C
- Coldest on record January -14 °C
What to expectSeattle through the year
Seattle has a clear annual cycle: average daily highs run from 9.1 °C in February to 25 °C in August, a swing of 15 °C in mean temperature across the year.
Counted across a normal year, 39 days a year reach 25 °C, 5 of them reach 30 °C, 33 nights drop below freezing. The warmest reading in the 1991–2020 record is 38 °C, in July.
Rain is strongly seasonal. November averages 192 mm against 25 mm in July — 7.6 times as much. Planning around the dry months matters more here than planning around temperature.
Month by month
| Month | Avg high | Rainfall | Cloud |
|---|---|---|---|
| January | 7.5 °C | 175 mm | 77 % |
| February | 9.1 °C | 119 mm | 70 % |
| March | 11.4 °C | 136 mm | 72 % |
| April | 14.2 °C | 111 mm | 69 % |
| May | 17.9 °C | 76 mm | 65 % |
| June | 20.6 °C | 59 mm | 62 % |
| July | 24.6 °C | 25 mm | 45 % |
| August | 24.9 °C | 34 mm | 45 % |
| September | 21.3 °C | 64 mm | 51 % |
| October | 15.2 °C | 129 mm | 66 % |
| November | 9.9 °C | 192 mm | 75 % |
| December | 6.9 °C | 176 mm | 77 % |
Temperature month by month
| Month | Avg high | Avg low | Mean | Record high | Record low | Days above 25 °C | Days above 30 °C | Days below 0 °C |
|---|---|---|---|---|---|---|---|---|
| January | 7.5 °C | 2.0 °C | 4.3 °C | 15.2 °C | -14.5 °C | 0 | 0 | 9 |
| February | 9.1 °C | 1.8 °C | 4.8 °C | 18.2 °C | -12.5 °C | 0 | 0 | 8 |
| March | 11.4 °C | 3.3 °C | 6.7 °C | 22.8 °C | -4.5 °C | 0 | 0 | 4 |
| April | 14.2 °C | 5.2 °C | 9.0 °C | 27.5 °C | -2.2 °C | 0 | 0 | 1 |
| May | 17.9 °C | 8.4 °C | 12.6 °C | 28.6 °C | 1.1 °C | 2 | 0 | 0 |
| June | 20.6 °C | 11.1 °C | 15.3 °C | 33.0 °C | 3.9 °C | 4 | 1 | 0 |
| July | 24.6 °C | 13.7 °C | 18.6 °C | 37.5 °C | 7.7 °C | 14 | 3 | 0 |
| August | 24.9 °C | 14.0 °C | 18.8 °C | 36.1 °C | 8.0 °C | 15 | 2 | 0 |
| September | 21.3 °C | 11.6 °C | 15.8 °C | 32.0 °C | 3.7 °C | 5 | 0 | 0 |
| October | 15.2 °C | 7.9 °C | 11.0 °C | 27.4 °C | -3.0 °C | 0 | 0 | 0 |
| November | 9.9 °C | 4.5 °C | 6.7 °C | 18.4 °C | -12.2 °C | 0 | 0 | 3 |
| December | 6.9 °C | 2.0 °C | 4.1 °C | 14.1 °C | -12.2 °C | 0 | 0 | 9 |
Rain, sun and wind month by month
| Month | Rainfall | Wet days | Daylight | Cloud cover | Humidity | Wind |
|---|---|---|---|---|---|---|
| January | 175 mm | 18 | 8.9 h/day | 77 % | 85 % | 16 km/h |
| February | 119 mm | 14 | 10 h/day | 70 % | 82 % | 16 km/h |
| March | 136 mm | 17 | 12 h/day | 72 % | 80 % | 16 km/h |
| April | 111 mm | 16 | 14 h/day | 69 % | 78 % | 15 km/h |
| May | 76 mm | 12 | 15 h/day | 65 % | 75 % | 14 km/h |
| June | 59 mm | 10 | 16 h/day | 62 % | 72 % | 13 km/h |
| July | 25 mm | 5 | 16 h/day | 45 % | 68 % | 12 km/h |
| August | 34 mm | 5 | 14 h/day | 45 % | 69 % | 12 km/h |
| September | 64 mm | 8 | 13 h/day | 51 % | 75 % | 13 km/h |
| October | 129 mm | 15 | 11 h/day | 66 % | 82 % | 15 km/h |
| November | 192 mm | 18 | 9.3 h/day | 75 % | 85 % | 17 km/h |
| December | 176 mm | 18 | 8.5 h/day | 77 % | 84 % | 17 km/h |
Where Seattle ranks
| Ranking | Position | Value |
|---|---|---|
| Places with the best weather in North America in August | 3rdof 50 | 94/100 |
| Places with the best weather in North America in July | 4thof 50 | 95/100 |
| The coolest places in North America in June | 14thof 50 | 21 °C |
| The coolest places in North America in May | 25thof 50 | 18 °C |
| Places with the best weather in North America in September | 29thof 50 | 90/100 |
| Places with the best weather in North America in June | 31stof 50 | 87/100 |
Planning a trip? See the best time to visit Seattle.
QuestionsCommon questions about Seattle’s climate
When is the best time to visit Seattle?
That depends on what you want, so the honest answer is a comparison rather than a single month. July, August, September sit closest to 20 °C on average, August is the warmest month and July the driest. The month-by-month table above has the full picture.
How hot does Seattle get?
In August, the warmest month, daily highs average 25 °C. About 5 days a year pass 30 °C. The highest value in the 1991–2020 record is 38 °C.
How cold does it get in winter?
Nights average 1.8 °C in February, the coldest month. A normal year has 33 nights below freezing.
Which month is wettest in Seattle?
November, averaging 192 mm over 18 days with rain. The driest month is July with 25 mm. The year as a whole averages 1,296 mm.
Are these figures a forecast?
No. They are 1991–2020 climate normals: the average of thirty years, which describes what a month is usually like in Seattle rather than what any particular week will bring. Individual years can differ substantially from the normal.
Data sources and method
- ERA5 / ERA5-Land reanalysis — Copernicus Climate Change Service (C3S), ECMWF. Copernicus Licence
- Open-Meteo — Open-Meteo.com. CC BY 4.0
- NOAA OISST v2.1 — NOAA Physical Sciences Laboratory. Public domain
- GeoNames — GeoNames.org. CC BY 4.0
- Normal period
- 1991–2020
- Dataset version
- era5-1991-2020-scores1.1
- Last processed
Measured values come from ERA5 reanalysis and are reproduced unchanged. Calculated by us: monthly rankings, daylight hours, beach and comfort scores. Full formulas are on the methodology page.
Contains modified Copernicus Climate Change Service information 2026. Neither the European Commission nor ECMWF is responsible for any use that may be made of the Copernicus information or data it contains.