San Antonio Weather Averages
Most of the year San Antonio, Texas basks in weather that's mainly warm, dry and sunny. The heat spikes during summer months, while rainfall peaks in spring and fall.
This page gives detailed information on the annual temperature, precipitation, sun, humidity, wind and storm averages 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.
|80 °F||annual average high||27 °C|
|59 °F||annual average low||15 °C|
San Antonio's coldest days of the year usually occur in late December early January when the daily maximum temperature averages 63 degrees Fahrenheit (17 degrees Celsius) and the minimum averages 41 °F (5 °C).
The year's hottest days are normally in mid August. The average temperature peaks then with daily highs of 97 °F (36 °C) and nighttime lows of 76 °F (24 °C).
|213 days||80 °F max. or more (27 °C)|
|110 days||50 °F min. or less (10 °C)|
San Antonio averages 122 days a year when the thermometer reaches into the 90s °F (over 32 °C). The temperature normally climbs above 100 °F (38 °C) on 18 days.
The thermometer dips to freezing or below on an average of 14 nights a year. San Antonio does not normally get as cold as 20 °F (-8 °C).
|32.4 in||total precipitation||822 mm|
|81 days||of rain or snowfall|
September and October are usually the wettest months of the year in San Antonio, while January and February are the driest.
San Antonio averages 0.2 inches (0.5 centimetres) of snow a year, which is most likely to fall in February. For most years though, the city sees no snow.
|105 days||clear skies|
The sun's rays reach the ground in San Antonio during 60 percent of daylight hours on average year round, for a total of 2665 hours annually. Typically on 105 days a year the sky is mainly clear, with at most 30 percent cloud cover.
Sunlight in San Antonio averages 12 hours and 9 minutes a day. The shortest days of the year in mid December have 10 hours and 16 minutes of daylight. The year's longest days in mid June last 14:02 from sunrise to sunset.
|67 %||average humidity|
The annual average for relative humidity in San Antonio ranges throughout the day from 83 percent at 6:00 am to 48 percent at 3:00 pm standard time.
|Local Time||12 am||3 am||6 am||9 am||12 pm||3 pm||6 pm||9 pm|
|9.1 mph||wind speed average||14.6 kph|
March and April are usually the windiest months for San Antonio, while the wind is calmest during September and October.
|9 days||precipitation of 1 inch (25 mm) or more|
|36 days||with thunderstorms a year|
Thunderstorms occur most often in May, but can appear over San Antonio any time of the year.
Although uncommon, major hurricanes have approached within 100 miles (165 km) of San Antonio during August and September.
The weather data here are long-term averages provided by the US National Centers for Environmental Information (NCEI). Temperature and precipitation are 1991-2020 normals while humidity and thunderstorms are 1961-1990 normals.