San Antonio Weather in August

The hot weather for San Antonio, Texas peaks in August. This is also one of the city's sunniest months.

This page gives detailed information on the typical August temperature, precipitation, sun, humidity, wind and storms for San Antonio. The numbers here are historical averages based on climate data gathered at the San Antonio International Airport, located a few miles north of the city center.

Temperature

96 °F	August average high	36 °C
75 °F	August average low	24 °C

August is San Antonio's hottest month overall, with temperatures peaking from the 2nd to 11th. These dates have daily highs averaging 97 degrees Fahrenheit (36 degrees Celsius) and lows of 76 °F (24 °C).

29 days	90 °F max. or more (32 °C)
2 days	70 °F min. or less (21 °C)

Usually every August day is over 80 °F (27 °C) at San Antonio. The city averages 9 days this month when the thermometer reaches into the 100s °F (over 38 °C).

August does not normally cool down as far as 60 °F (16 °C) at night.

Rain

2.2 in	total precipitation	55 mm
5 days	of rain

Half the time, San Antonio receives 0.4 to 2.8 inches (9 to 70 mm) of rainfall in August. One in four years has drier weather, while another one in four is wetter.

Sun

74 %	sunshine
10 days	clear skies

August is one of the sunniest months for San Antonio. The sun's rays reach the ground during 74 percent of daylight hours on average, for a monthly total of 302 hours. Typically on 10 days this month the sky is mainly clear, with at most 30 percent cloud cover.

Sunlight in August at San Antonio lasts for 13 hours and 9 minutes a day on average. The longest day of the month is the 1st with 13 hours and 32 minutes of daylight. By the end of the month, the days have shortened to 12:46 from sunrise to sunset. These durations can vary by a minute or two from year to year.

Humidity

65 %	August average humidity

The relative humidity in San Antonio during August usually peaks at 86 percent in the morning then drops to 44 percent by mid afternoon.

Local Time	12 am	3 am	6 am	9 am	12 pm	3 pm	6 pm	9 pm
Humidity %	74	82	86	72	53	44	46	61

Wind

8.4 mph

August wind speed average

13.5 kph

August is less windy than most other months in San Antonio.

Storms

1 day	rainfall of 0.5 inches (13 mm) or more
4 days	with thunderstorms in August
6 %	chance a named storm approaches

There's a 2 percent probability that a hurricane will approach within 100 miles (165 km) of San Antonio during August. The chance of a major hurricane (category 3 to 5) reaching the area is 1 percent.