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San Francisco vs Seattle weather: climate comparison
San Francisco is the warmer of the two, averaging 57°F (14°C) over the year against 52°F (11°C) in Seattle. Seattle is wetter, with 50.2 in (1275 mm) of precipitation a year to San Francisco's 20.3 in (515 mm). Below: every month side by side, from 30 years of ERA5 data (1996–2025).
- Mean temperature
- 14.0°C San Francisco
10.9°C Seattle - Annual precipitation
- 514.5 mm San Francisco
1274.6 mm Seattle - Rainy days a year
- 56 San Francisco
154 Seattle - Sunshine per day
- 10.5 h San Francisco
8.3 h Seattle
Month by month
| Month | San Francisco | Seattle |
|---|---|---|
| January | 13.6°C | 7.3°C |
| February | 14.4°C | 8.4°C |
| March | 15.5°C | 10.6°C |
| April | 16.6°C | 13.4°C |
| May | 18.3°C | 16.9°C |
| June | 20.2°C | 20.0°C |
| July | 20.5°C | 24.0°C |
| August | 21.2°C | 24.2°C |
| September | 22.0°C | 20.4°C |
| October | 20.5°C | 14.6°C |
| November | 16.4°C | 9.8°C |
| December | 13.5°C | 6.9°C |
Year at a glance
| Measure | San Francisco | Seattle |
|---|---|---|
| Mean annual temperature | 14.0°C | 10.9°C |
| Warmest month (avg high) | Sep · 22°C | Aug · 24°C |
| Coldest month (avg low) | Jan · 7°C | Feb · 2°C |
| Annual range (warmest high − coldest low) | 15°C | 22°C |
| Annual precipitation | 514.5 mm | 1274.6 mm |
| Rainy days per year | 56 | 154 |
| Wettest / driest month | Dec / Jul | Nov / Jul |
| Average sunshine per day | 10.5 h | 8.3 h |
In short: San Francisco is the warmest overall (14.0°C mean); Seattle gets the most precipitation (1274.6 mm a year); San Francisco is the sunniest (10.5 h a day on average); San Francisco has the smallest swing between its warmest and coldest months.
Record high 1996–2025: San Francisco 38.5°C (2017-09-02), Seattle 37.9°C (2021-06-28). Record low: San Francisco -2.3°C (1998-12-21), Seattle -14.5°C (1996-01-30).
Source: Open-Meteo Historical Weather API (CC BY 4.0). Values are ERA5 reanalysis model data on a ~9–25 km grid, not readings from a weather station, so a single town’s thermometer can differ by a few degrees and local showers can be missed. Monthly means of daily ERA5 values, 1996–2025, for the grid cells nearest San Francisco (37.79, -122.41) and Seattle (47.63, -122.32).
Which months differ most?
The gap in average highs is widest in November, when San Francisco runs 12°F / 7°C warmer, and narrowest in June (0°F / 0°C apart). The biggest rainfall difference is in November: Seattle gets 5.3 in (135 mm) more on average.
Add a third or fourth city, or swap in any other place, in the full comparison tool. For one city in depth, see the San Francisco climate and Seattle climate pages.
Compare San Francisco or Seattle with another city
Questions people ask
Is San Francisco warmer than Seattle?
San Francisco is warmer on average: its mean annual temperature is 57°F (14°C) against 52°F (11°C) in Seattle (ERA5, 1996–2025).
Which gets more rain, San Francisco or Seattle?
Seattle, with about 50.2 in (1275 mm) of precipitation a year and 154 days with at least 1 mm, compared with 20.3 in (515 mm) and 56 days in San Francisco.
Which is sunnier, San Francisco or Seattle?
San Francisco averages more sunshine: 10.5 h a day against 8.3 h. Sunshine duration is modelled from cloud cover.
How reliable is this comparison?
Both cities use the same 30-year reanalysis, so differences are consistent. Absolute values describe a grid cell several kilometres wide and can differ by a degree or two from the airport station.