Here’s a summary of the weather in San Antonio for September 2025:
In September 2025, San Antonio’s weather remained warm and largely characteristic of late summer, with daytime highs generally in the mid-80s to upper-80s °F and nighttime lows mostly in the low 70s °F, reflecting a gradual seasonal cooling from summer extremes. Average temperatures for the month hovered around the 80 °F range—typical for September in the region. There were several rain events early in the month, including moderate to heavy showers and thunderstorms that brought showers and even caused localized power outages around September 7, but overall rainfall was below the month’s climatological average, with many dry stretches between precipitation events. 🌦️ The persistence of warm conditions and sunshine made September feel more like an extended summer than fall, although cloud cover and humidity slowly lessened as the month progressed and daylight hours shortened. (weatherspark.com)