Climate averages 1991–2020
San Antonio weather
in August.
A very hot, moderately wet month: the warmest and one of the driest of the year.
Long-term climate patterns, not a forecast for a particular trip.
August is a very hot month in San Antonio: daytime highs average 35.1°C and nights cool to about 24.7°C. By daytime temperature it is the warmest month of the year.
Expect about 50 mm of rain on roughly 6 days, which makes August a moderately wet month (one of the driest months of the year). Daylight, from sunrise to sunset, lasts about 13 h 12 min on an average August day.
The nearest other city in this atlas is New Braunfels (47 km away). In August its highs average 34.9°C, about as warm as San Antonio, with 56 mm of rain.
Among the 498 cities listed in the United States, San Antonio ranks joint 30th of 498 for the warmest August highs and joint 191st of 498 for the driest August (rainfall, lowest first). The mean August high of those 498 cities is 29.9°C; San Antonio is 5.2°C warmer than that mean.
From August to September, average highs fall by 3.5°C to 31.6°C, and monthly rainfall rises from 50 mm to 77 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 Antonio climate table
| Month | Average highHigh / low | Average low | Rainfall mm/month | Rain days ≥1 mm/day | Daylight hours/dayDaylight h/day |
|---|---|---|---|---|---|
| January | 16.9°C6.7°C | 6.7°C | 57 | 7.2 | 10.510 h |
| February | 19.3°C8.7°C | 8.7°C | 59 | 7.5 | 11.111 h |
| March | 22.8°C12.1°C | 12.1°C | 79 | 9.2 | 12.012 h |
| April | 26.6°C15.7°C | 15.7°C | 78 | 8.5 | 12.913 h |
| May | 29.9°C19.9°C | 19.9°C | 103 | 11.2 | 13.614 h |
| June | 33.0°C23.1°C | 23.1°C | 69 | 9.5 | 14.014 h |
| July | 34.5°C24.1°C | 24.1°C | 50 | 6.1 | 13.814 h |
| August, selected | 35.1°C24.7°C | 24.7°C | 50 | 5.8 | 13.213 h |
| September | 31.6°C22.0°C | 22.0°C | 77 | 8.6 | 12.412 h |
| October | 27.3°C17.3°C | 17.3°C | 83 | 7.7 | 11.511 h |
| November | 21.5°C11.7°C | 11.7°C | 67 | 7.2 | 10.711 h |
| December | 17.5°C7.8°C | 7.8°C | 63 | 7.5 | 10.310 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
- New Braunfels in AugustUnited States · 47 kmHigh 34.9°C · Low 24.5°C · 56 mm rain
- Austin in AugustUnited States · 118 kmHigh 35.0°C · Low 24.8°C · 59 mm rain
- Round Rock in AugustUnited States · 144 kmHigh 34.7°C · Low 24.6°C · 54 mm rain
- Killeen in AugustUnited States · 202 kmHigh 34.4°C · Low 24.6°C · 53 mm rain
- Corpus Christi in AugustUnited States · 210 kmHigh 33.1°C · Low 25.8°C · 59 mm rain
- Piedras Negras in AugustMexico · 213 kmHigh 36.8°C · Low 26.4°C · 46 mm rain
- Temple in AugustUnited States · 216 kmHigh 34.6°C · Low 24.7°C · 58 mm rain
- Ciudad Acuña in AugustMexico · 238 kmHigh 36.0°C · Low 26.1°C · 41 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 Antonio) is explained once on the San Antonio year overview and on the Sources, method and limits page.