Weather in San Antonio in September
September in San Antonio is warm with average temperatures around 26.5°C (79.7°F). Moderate rainfall of 95mm spread over 10 days.
Data Note: Temperature values are 2001–2020 satellite/reanalysis grid averages from NASA POWER and may differ from airport station normals by a few degrees.
Temperature
High
32.2°C
90.0°F
Low
20.9°C
69.6°F
Precipitation
95 mm
3.8 inches
~10 rainy days
Conditions
Humidity
68%
Comparison to Adjacent Months
September is 3.5°C cooler than August, 34mm wetter than August.
September is 4.6°C warmer than October.