WeatherArchive / Climate averages / San Diego
San Diego climate: average weather by month
San Diego averages 63°F (17°C) over the year. August is warmest, with highs around 78°F (25°C); January is coldest, with lows near 47°F (9°C). About 12 inches (298 mm) of precipitation falls on roughly 38 days a year, from 30 years of ERA5 data (1996–2025).
| Month | Avg high | Avg low | Precip. | Days ≥1 mm | Sunshine / day |
|---|---|---|---|---|---|
| January | 17.5°C | 8.6°C | 50.5 mm | 5.2 | 8.9 h |
| February | 17.3°C | 9.1°C | 63.2 mm | 6.3 | 9.3 h |
| March | 17.8°C | 10.3°C | 43.4 mm | 5.8 | 10.8 h |
| April | 19.1°C | 11.8°C | 22.4 mm | 3.9 | 11.6 h |
| May | 20.2°C | 13.7°C | 9.8 mm | 2.1 | 12.2 h |
| June | 21.9°C | 15.2°C | 1.6 mm | 0.5 | 13.0 h |
| July | 24.3°C | 17.4°C | 2.9 mm | 0.5 | 13.2 h |
| August | 25.3°C | 18.2°C | 4.1 mm | 0.7 | 12.4 h |
| September | 25.0°C | 17.7°C | 8.3 mm | 1.2 | 11.4 h |
| October | 23.1°C | 15.1°C | 15.6 mm | 2.4 | 10.4 h |
| November | 20.4°C | 11.6°C | 27.9 mm | 3.5 | 9.5 h |
| December | 17.5°C | 8.9°C | 48.7 mm | 5.5 | 8.6 h |
Record high 1996–2025: 36.6°C on 2020-09-30. Record low: 1.8°C on 2007-01-15.
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. Grid cell 32.72, -117.14 at 20 m. For snowfall, humidity and a best-time-to-visit score, open San Diego in the climate tool.