August weather forecast
San Antonio, TX

Buildings in San Antonio, Texas, with a calm view of the bridges across the waterfront
Buildings in San Antonio, Texas, with a calm view of the bridges across the waterfront

Weather in August

August, the last month of the summer in San Antonio, is another torrid month, with an average temperature ranging between max 96.6°F (35.9°C) and min 75.7°F (24.3°C).

Temperature

August is the warmest month, with an average high-temperature of 96.6°F (35.9°C) and an average low-temperature of 75.7°F (24.3°C).

Heat index

The average heat index in August is computed to be a blazing hot 116.6°F (47°C). Beware: Heat cramps and heat exhaustion are very likely. Heatstroke is imminent with prolonged activity.
Note that heat index values are valued for light wind and location in the shade. With exposure to direct sunlight, the heat index may be increased by up to 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'real feel', 'felt air temperature', 'feels like', or 'apparent temperature', is an index that combines air temperature and relative humidity to determine the human-perceived temperature equivalent. Additional factors like clothing, metabolic differences, wind, and activity influence one's weather impression. Bear in mind that direct sunshine exposure increases weather impact, and may raise heat index by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values are especially crucial for babies and toddlers. Children are often less aware of the need to rest and re-hydrate. Thirst is a late sign of dehydration - it is vital to remain hydrated, particularly during prolonged physical activities.
To prevent overheating and help regulate its internal temperature, the human body sweat and rely on the evaporation to cool down. A higher relative humidity affects normal body cooling by reducing the evaporation rate, subsequently lowering the rate at which the body cools and increasing the perception of heat. When heat gain exceeds the level the body can remove, body temperature begins to rise, and heat-related illnesses and disorders may develop.

Humidity

The least humid month is August, with an average relative humidity of 59%.

Rainfall

In August, the rain falls for 9.8 days. Throughout August, 1.5" (38mm) of precipitation is accumulated. Throughout the year, there are 144.5 rainfall days, and 22.6" (574mm) of precipitation is accumulated.

Snowfall

March through November are months without snowfall in San Antonio.

Daylight

In San Antonio, the average length of the day in August is 13h and 10min.
On the first day of August in San Antonio, sunrise is at 6:54 am and sunset at 8:26 pm. On the last day of the month, sunrise is at 7:10 am and sunset at 7:57 pm CDT.

Sunshine

In August, the average sunshine is 9.9h.

UV index

June through August, with an average maximum UV index of 7, are months with the highest UV index. A UV Index estimate of 6 to 7 represents a high health risk from exposure to the Sun's UV rays for average individuals.
Note: The daily maximum UV index of 7 in August interpret into the following advice:
Take precautions and adopt sun safety practices. Protection against sunburn is obliged. Seek shade and minimize exposure to direct Sun in a period between 10 a.m. and 4 p.m. when UV radiation is most intense; keep in mind that shade structures like parasols or canopies do not provide perfect sun protection. On bright days sunglasses that block both UVA and UVB rays should be worn. A hat with a wide brim is extremely helpful, as it can prevent roughly 50% of UV radiation from reaching the eyes.
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FAQ

What is the warmest month in San Antonio?

With an average high-temperature of 96.6°F (35.9°C) and an average low-temperature of 75.7°F (24.3°C), August is the warmest month in San Antonio, Texas.

What is the temperature in August in San Antonio?

In San Antonio, Texas, in August, the average high-temperature is 96.6°F (35.9°C), and the average low-temperature is 75.7°F (24.3°C). in August, the average heat index (a.k.a. 'apparent temperature', 'feels like'), which represents the influence of relative humidity on air temperature, is computed to be 116.6°F (47°C).

What is the least humid month in San Antonio?

The least humid month in San Antonio, Texas, is August, with an average relative humidity of 59%.

What is the average humidity in August in San Antonio?

In August, the average relative humidity in San Antonio, Texas, is 59%.

How many days does it rain in August in San Antonio?

In San Antonio, in August, it is raining for 9.8 days, with typically 1.5" (38mm) of accumulated precipitation.

When it does not snow in San Antonio?

In San Antonio, snow does not fall in March through November.

What is the average length of the day in August in San Antonio?

The average day length in August in San Antonio is 13h and 10min.

When is the sunrise / sunset in August in San Antonio?

In August, on the first day of the month, sunrise is at 6:54 am and sunset at 8:26 pm. On the last day of the month, sunrise is at 7:10 am and sunset at 7:57 pm CDT.

How many hours of sunshine does San Antonio have in August?

In August, the average sunshine duration in San Antonio, Texas, is 9.9h.

When is the highest UV index in San Antonio?

June through August, with an average maximum UV index of 7, are months with the highest UV index in San Antonio, Texas.

How high is the UV index in August in San Antonio?

In August, the average daily maximum UV index in San Antonio, Texas, is 7. A UV Index value of 6 to 7 symbolizes a high health threat from unsafe exposure to Sun's UV rays.
Average humidity
Average rainfall days
Average snowfall
Average snowfall days
Average sunshine days
Average UV index
Average cloud cover
Average visibility

Average temperature in August
San Antonio, TX

Average temperature in August - San Antonio, TX
  • Average high temperature in August: 96.6°F

The warmest month (with the highest average high temperature) is August (96.6°F).
The month with the lowest average high temperature is January (61.7°F).

  • Average low temperature in August: 75.7°F

The month with the highest average low temperature is August (75.7°F).
The coldest month (with the lowest average low temperature) is January (44.2°F).

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Average pressure in August
San Antonio, TX

Average pressure in August - San Antonio, TX
  • Average pressure in August: 29.91"Hg

The month with the highest atmospheric pressure is January (30.15"Hg).
The month with the lowest atmospheric pressure is June (29.89"Hg).

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Average wind speed in August
San Antonio, TX

Average wind speed in August - San Antonio, TX
  • Average wind speed in August: 7.1mph

The windiest month (with the highest average wind speed) is May (9mph).
The calmest month (with the lowest average wind speed) is September (6.5mph).

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Average humidity in August
San Antonio, TX

Average humidity in August - San Antonio, TX
  • Average humidity in August: 59%

The month with the highest relative humidity is May (73%).
The month with the lowest relative humidity is August (59%).

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Average rainfall in August
San Antonio, TX

Average rainfall in August - San Antonio, TX
  • Average rainfall in August: 1.5"

The wettest month (with the highest rainfall) is May (3.66").
The driest month (with the least rainfall) is February (0.98").

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Average rainfall days in August
San Antonio, TX

Average rainfall days in August - San Antonio, TX
  • Average rainfall days in August: 9.8 days

The month with the highest number of rainy days is September (17 days).
The month with the least rainy days is January (9.1 days).

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Average snowfall in August
San Antonio, TX

Average snowfall in August - San Antonio, TX
  • Average snowfall in August: 0"

The months with the highest snowfall are January and February (0.08").
The months with the least snowfall are March, April, May, June, July, August, September, October and November (0").

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Average snowfall days in August
San Antonio, TX

Average snowfall days in August - San Antonio, TX
  • Average snowfall days in August: 0 days

The months with the highest number of snowfall days are January and February (0.3 days).
The months with the least snowfall days are March, April, May, June, July, August, September, October and November (0 days).

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Average daylight in August /
Average sunshine in August
San Antonio, TX

Average daylight in August / Average sunshine in August - San Antonio, TX
  • Average daylight in August: 13h and 10min

The month with the longest days is June (Average daylight: 14h and 0min).
The month with the shortest days is December (Average daylight: 10h and 18min).

  • Average sunshine in August: 9h and 54min

The month with the most sunshine is July (Average sunshine: 10h and 18min).
The month with the least sunshine is December (Average sunshine: 5h and 18min).

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Average sunshine days in August
San Antonio, TX

Average sunshine days in August - San Antonio, TX
  • Average sunshine days in August: 19.8 days

The month with the most sunshine days is January (20.3 days).
The months with the least sunshine days are May and September (11.8 days).

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Average UV index in August
San Antonio, TX

Average UV index in August - San Antonio, TX
  • Average UV index in August: 7

The months with the highest UV index are June, July and August (UV index 7).
The month with the lowest UV index is December (UV index 3).

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Average cloud cover in August
San Antonio, TX

Average cloud cover in August - San Antonio, TX
  • Average cloud cover in August: 23

The month with the most cloud cover is March (Cloud cover 47).
The month with the least cloud cover is August (Cloud cover 23).

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Average visibility in August
San Antonio, TX

Average visibility in August - San Antonio, TX
  • Average visibility in August: 6mi

The months with the highest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
The months with the lowest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).

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