San Antonio Weather in September

What's the weather like in San Antonio (Texas) in September 2025?

The climate in San Antonio during September can be summarized as hot and a little damp.

September is in the fall / autumn in San Antonio and is typically the 4th warmest month of the year. Daytime maximum temperatures average around a warm 32°C (90°F), whilst at night 21°C (69°F) is normal.

San Antonio weather averages (imperial / metric)
Daytime temperature 32°C 89.5°F
Nightly temperature 20.5°C 68.8°F
Average temperature 26.2°C 79.2°F
Daily sunshine 8.3 hrs
Avg rainfall 90 mm 3.5 ins
Rainy days 7 days
Sea temperature 28.8°C 83.8°F
Humidity 69%
Windspeed 14.8kph 9 mph

On average September is the 2nd wettest month of the year in San Antonio with around 90mm 3.5 inches of rain making it a a little damp time to visit. This rainfall is typically spread over 7 days, although this may vary considerably.

On the flip side this corresponds to an average of 8.3 hours of sunshine per day.

September temperatures in San Antonio

San Antonio average temperature in September

September rainfall

San Antonio average rain in September

September hourly sunshine

San Antonio average rain in September

The data used in these monthly averages covers a period of over 100 years right up until last year. As such they are a valid prediction of what to expect for the weather in San Antonio in September 2025.

Other monthly averages

Best places to visit in September

UV index Best time to go?

Beta

Current (hourly) weather 15 day forecast

San Antonio weather stats

San Antonio weather statistics
Hottest month: July 34.8°C 94.6°F
Driest month: March 37mm 1.5ins
Sunniest month: July 10.6hrs
Coldest month: January 15.8°C 60.4°F
Wettest month: May 94mm 3.7ins
Map showing location of San Antonio (29.42412, -98.49363) San Antonio map pin © Google

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