Climate averages 1991–2020
San Diego weather
in August.
A warm, very dry month: the warmest and the driest of the year. Meets the pleasant-weather rule
Long-term climate patterns, not a forecast for a particular trip.
August is a warm month in San Diego: daytime highs average 25.4°C and nights cool to about 18.0°C. By daytime temperature it is the warmest month of the year.
Rain is very rare: less than 1 mm falls in a typical August (the driest month of the year). Daylight, from sunrise to sunset, lasts about 13 h 21 min on an average August day.
The nearest other city in this atlas is Chula Vista (11 km away). In August its highs average 24.5°C, 0.9°C cooler than San Diego, with 1.8 mm of rain.
Among the 498 cities listed in the United States, San Diego ranks joint 465th of 498 for the warmest August highs and joint 13th of 498 for the driest August (rainfall, lowest first). The mean August high of those 498 cities is 29.9°C; San Diego is 4.5°C cooler than that mean.
From August to September, average highs fall by 0.4°C to 25.1°C, and monthly rainfall rises from under 1 mm to 2.9 mm.
The annual picture
August in context
Monthly rainfall
Average total · mmAverages from hourly ERA5 reanalysis data. Actual weather varies from year to year. How these numbers are calculated
Every month, side by side
San Diego climate table
| Month | Average highHigh / low | Average low | Rainfall mm/month | Rain days ≥1 mm/day | Daylight hours/dayDaylight h/day |
|---|---|---|---|---|---|
| January | 17.4°C8.7°C | 8.7°C | 50 | 5.5 | 10.310 h |
| February | 17.2°C9.2°C | 9.2°C | 63 | 6.1 | 11.011 h |
| March | 17.8°C10.4°C | 10.4°C | 38 | 5.2 | 12.012 h |
| April | 19.1°C11.9°C | 11.9°C | 16 | 2.9 | 13.013 h |
| May | 20.2°C13.6°C | 13.6°C | 7.1 | 1.6 | 13.814 h |
| June | 22.0°C14.9°C | 14.9°C | 1.2 | 0.2 | 14.314 h |
| July | 24.3°C17.1°C | 17.1°C | 1.3 | 0.3 | 14.114 h |
| August, selected | 25.4°C18.0°C | 18.0°C | 0.4 | 0.1 | 13.413 h |
| September | 25.1°C17.5°C | 17.5°C | 2.9 | 0.6 | 12.412 h |
| October | 23.0°C15.2°C | 15.2°C | 12 | 2.0 | 11.411 h |
| November | 20.3°C11.7°C | 11.7°C | 19 | 2.9 | 10.511 h |
| December | 17.3°C8.8°C | 8.8°C | 40 | 4.9 | 10.010 h |
Rainfall is the average of the 30 separate monthly totals. A rain day is a local calendar day with at least 1 mm of precipitation. Daylight is the calculated sunrise-to-sunset length, not measured sunshine.
Compare places
August in nearby cities
- Chula Vista in AugustUnited States · 11 kmHigh 24.5°C · Low 18.1°C · 1.8 mm rain
- El Cajon in AugustUnited States · 21 kmHigh 28.3°C · Low 18.7°C · 1.8 mm rain
- Tijuana in AugustMexico · 28 kmHigh 24.8°C · Low 18.6°C · 1.2 mm rain
- Rosarito in AugustMexico · 41 kmHigh 24.9°C · Low 19.3°C · 0.4 mm rain
- Escondido in AugustUnited States · 45 kmHigh 29.1°C · Low 18.8°C · 2.6 mm rain
- San Marcos in AugustUnited States · 48 kmHigh 26.9°C · Low 18.2°C · 1.0 mm rain
- Vista in AugustUnited States · 54 kmHigh 28.9°C · Low 19.4°C · 1.0 mm rain
- Oceanside in AugustUnited States · 57 kmHigh 25.8°C · Low 19.1°C · 0.6 mm rain
Read the numbers correctly
Climate, not a promise.
These patterns help compare months. They cannot tell you the weather on a specific day of your trip.
Sources, method and limitsHow these numbers are made (what the highs, lows and rain days mean, the sources and the model cell used for San Diego) is explained once on the San Diego year overview and on the Sources, method and limits page.