San Antonio weather in August: San Antonio, Texas: normal highs, lows, rain and records for August
San Antonio in August has a normal high of 96°F and a normal low of 75°F, a daily mean of 86°F, falling from 97°F on the 1st to 94°F by the 31st. Measurable precipitation falls on 5 days in a normal August, 2.15 inches in all. (NOAA 1991-2020 normals)
In metric: a normal high of 36°C and low of 24°C, 55 mm of precipitation in August.
- NOAA stationSan Antonio International Airport
- Station IDUSW00012921
- Location29.54°N 98.48°W
- Elevation789 ft (241 m)
- From the center6 miles
- Population1,526,656
- Jan 63° 41°
- Feb 68° 45°
- Mar 74° 52°
- Apr 80° 58°
- May 87° 66°
- Jun 92° 73°
- Jul 95° 75°
- Aug 96° 75°
- Sep 90° 70°
- Oct 82° 60°
- Nov 72° 50°
- Dec 65° 42°
Each month: normal high (large) and low, °F. Fill: the month's normal mean, colder blue to hotter red.
How warm is San Antonio in August?
The normal high is 96°F and the normal low 75°F, for a daily mean of 85.5°F. August is 0.7°F warmer than July and 5.6°F warmer than September. August is the warmest month of the year in San Antonio and the 8th wettest. Across the month the normal high falls 3°F, from 97°F on August 1 to 94°F on August 31. From one year to the next August's mean temperature typically moves about 2.0°F either way (NOAA's standard deviation), so roughly two Augusts in three average between 84°F and 88°F.
Bars above: each day's normal high to low. Columns below: the chance of 0.01 inch or more of precipitation that day, on a scale of 0 to 100% (highest 21%).
| Day | High | Low | Chance of 0.01 in | Chance of 0.10 in |
|---|---|---|---|---|
| August 1 | 97°F | 75°F | 14% | 8% |
| August 8 | 97°F | 76°F | 14% | 9% |
| August 15 | 97°F | 75°F | 16% | 10% |
| August 22 | 96°F | 75°F | 18% | 12% |
| August 31 | 94°F | 73°F | 21% | 14% |
Every day of August: normal high, low and chance of precipitation (warmest afternoon August 5, coldest night August 31)
| Day | High | Low | Chance of 0.01 in | Chance of 0.10 in | Daylight |
|---|---|---|---|---|---|
| August 1 | 97°F | 75°F | 14% | 8% | 13 h 30 min |
| August 2 | 97°F | 76°F | 14% | 8% | 13 h 30 min |
| August 3 | 97°F | 76°F | 14% | 8% | 13 h 30 min |
| August 4 | 97°F | 76°F | 14% | 8% | 13 h 30 min |
| August 5 | 97°F | 76°F | 14% | 8% | 13 h 30 min |
| August 6 | 97°F | 76°F | 14% | 8% | 13 h 30 min |
| August 7 | 97°F | 76°F | 14% | 8% | 13 h 30 min |
| August 8 | 97°F | 76°F | 14% | 9% | 13 h 20 min |
| August 9 | 97°F | 76°F | 14% | 9% | 13 h 20 min |
| August 10 | 97°F | 76°F | 15% | 9% | 13 h 20 min |
| August 11 | 97°F | 76°F | 15% | 9% | 13 h 20 min |
| August 12 | 97°F | 75°F | 15% | 9% | 13 h 20 min |
| August 13 | 97°F | 75°F | 15% | 10% | 13 h 20 min |
| August 14 | 97°F | 75°F | 15% | 10% | 13 h 20 min |
| August 15 | 97°F | 75°F | 16% | 10% | 13 h 10 min |
| August 16 | 97°F | 75°F | 16% | 10% | 13 h 10 min |
| August 17 | 96°F | 75°F | 16% | 11% | 13 h 10 min |
| August 18 | 96°F | 75°F | 17% | 11% | 13 h 10 min |
| August 19 | 96°F | 75°F | 17% | 11% | 13 h 10 min |
| August 20 | 96°F | 75°F | 17% | 11% | 13 h 10 min |
| August 21 | 96°F | 75°F | 18% | 12% | 13 h 10 min |
| August 22 | 96°F | 75°F | 18% | 12% | 13 h |
| August 23 | 95°F | 75°F | 18% | 12% | 13 h |
| August 24 | 95°F | 74°F | 19% | 13% | 13 h |
| August 25 | 95°F | 74°F | 19% | 13% | 13 h |
| August 26 | 95°F | 74°F | 19% | 13% | 13 h |
| August 27 | 95°F | 74°F | 20% | 13% | 13 h |
| August 28 | 94°F | 74°F | 20% | 14% | 12 h 50 min |
| August 29 | 94°F | 74°F | 20% | 14% | 12 h 50 min |
| August 30 | 94°F | 74°F | 21% | 14% | 12 h 50 min |
| August 31 | 94°F | 73°F | 21% | 14% | 12 h 50 min |
- Normal high
- 96°FAugust average
- Normal low
- 75°FAugust average
- Precipitation
- 2.15 inmonth total
- Days with precipitation
- 50.01 inch or more
- Days at 90°F or more
- 29
- Daylight
- 13 h 30 min to 12 h 50 minAugust 1 to August 31
- Days at 70°F or more
- 31
- Days at 80°F or more
- 31
- Sunshine
- 88%of clear-sky sunlight (NASA)
Source: NOAA NCEI 1991-2020 daily normals, station USW00012921; monthly normals. Daylight is computed from the place's latitude with NOAA's solar equations.
Does it rain in San Antonio in August?
On a given August day the chance of 0.01 inch or more is 16% on average, highest around August 31 (21%). In all, 2.15 in falls on 5 days of a normal August, 1 of them with an inch or more.
In a normal August in San Antonio, 29 days reach 90°F.
Source: NOAA NCEI 1991-2020 daily and monthly normals, station USW00012921.
How humid and windy is San Antonio in August?
At 3 p.m. the normal temperature is 93°F with 40% relative humidity and a dew point of 65°F; at 6 a.m. it is 75°F with 84% humidity. The wind averages 7.4 mph, most often from the east-southeast in the afternoon. A dew point of 65°F or more feels muggy to most people.
| Time | Temperature | Dew point | Humidity | Wind | Clear or few clouds |
|---|---|---|---|---|---|
| 6 a.m. | 75°F | 70°F | 84% | 4.7 mph | 34% |
| 9 a.m. | 82°F | 71°F | 68% | 7.2 mph | 32% |
| noon | 89°F | 68°F | 49% | 8.0 mph | 29% |
| 3 p.m. | 93°F | 65°F | 40% | 9.3 mph | 26% |
| 6 p.m. | 90°F | 65°F | 44% | 10.1 mph | 38% |
| 9 p.m. | 83°F | 68°F | 60% | 8.5 mph | 47% |
Source: NOAA NCEI 1991-2020 hourly normals, station USW00012921. Hourly normals exist only for NOAA's first-order stations; a dash where NOAA publishes no value for that hour (the sky at some hours).
What are the records for August in San Antonio?
The warmest August temperature on San Antonio's official record (since 1885) is 110°F, on August 28, 2011; the coldest is 57°F, on August 24, 1891. The wettest August brought 11.14 in (1974).
The August mean against the 1991-2020 normal of 85.5°F: 2021 85.4°F (−0.1), 2022 86.8°F (+1.3), 2023 90.7°F (+5.2), 2024 88.7°F (+3.2), 2025 87.5°F (+2.0), 2026 88.3°F (+2.8). 5 of 6 ran warmer than normal.
| August | Mean | Against normal | Precip. |
|---|---|---|---|
| 2021 | 85.4°F | −0.1°F | 1.28 in |
| 2022 | 86.8°F | +1.3°F | 2.10 in |
| 2023 | 90.7°F | +5.2°F | 0.94 in |
| 2024 | 88.7°F | +3.2°F | 0.38 in |
| 2025 | 87.5°F | +2.0°F | 3.55 in |
| 2026 | 88.3°F | +2.8°F | 1.75 in |
Source: records: ACIS, NWS threaded record SATthr; recent months: ACIS, station USW00012921. Records and recent months use complete months only.
How does August in San Antonio compare across Texas?
Across the 321 places PlainClimate covers in Texas, August normal highs run from 87°F in Marfa to 101°F in Del Rio; San Antonio's is 96°F.
Source: NOAA NCEI 1991-2020 monthly normals for every station in the state.