Austin weather in September
September in Austin: sweltering, a little rain, with clean air — a good time to visit.
#9 of 12 months in Austin · #431 of 604 destinations to visit in September · comfort 69/100 (tier C)
Updated June 2026 · climate normals from ERA5 reanalysis
Austin climate normals — September
| Daytime high | 33°C / 92°F | 🔥 sweltering |
|---|---|---|
| Nighttime low | 23°C / 74°F | |
| Feels like (high) | 36°C / 97°F | |
| Rainfall | 59 mm / 2.3 in | 🌦 some rain |
| Rainy days | 7 days | |
| Humidity | 57% | 🍃 comfortable |
| Dew point | 18°C / 65°F | |
| Sunshine | 10.4 h/day | |
| Daylight | 12.3 h | |
| Wind | 16 km/h / 10 mph | |
| Air quality (US AQI) | 44 | 🍃 good |
Monthly averages from ERA5 reanalysis. AQI is the mean US Air Quality Index for the month.
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Austin in September — FAQ
- Is September a good time to visit Austin?
- September in Austin: sweltering, a little rain, with clean air — a good time to visit. It ranks #9 of 12 months for Austin on SeasonMap's comfort score (69/100).
- What is the weather like in Austin in September?
- In September, Austin averages a daily high of 33.4°C and a low of 23.2°C, with about 58.8 mm of rain over roughly 7.4 rainy days.
- What is the air quality in Austin in September?
- Austin has a mean US Air Quality Index of about 44 in September.