Big Bend National Park weather in September
September in Big Bend National Park: hot, dry, with clean air — an excellent time to visit.
#8 of 12 months in Big Bend National Park · #298 of 604 destinations to visit in September · comfort 80/100 (tier A)
Updated June 2026 · climate normals from ERA5 reanalysis
Big Bend National Park climate normals — September
| Daytime high | 30°C / 86°F | 🥵 hot |
|---|---|---|
| Nighttime low | 19°C / 66°F | |
| Feels like (high) | 29°C / 84°F | |
| Rainfall | 19 mm / 0.7 in | ☀️ dry |
| Rainy days | 4 days | |
| Humidity | 43% | 🍃 comfortable |
| Dew point | 10°C / 49°F | |
| Sunshine | 11.2 h/day | |
| Daylight | 12.3 h | |
| Wind | 14 km/h / 9 mph | |
| Air quality (US AQI) | 38 | 🍃 good |
Monthly averages from ERA5 reanalysis. AQI is the mean US Air Quality Index for the month.
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Big Bend National Park in September — FAQ
- Is September a good time to visit Big Bend National Park?
- September in Big Bend National Park: hot, dry, with clean air — an excellent time to visit. It ranks #8 of 12 months for Big Bend National Park on SeasonMap's comfort score (80/100).
- What is the weather like in Big Bend National Park in September?
- In September, Big Bend National Park averages a daily high of 30.2°C and a low of 18.8°C, with about 19 mm of rain over roughly 3.8 rainy days.
- What is the air quality in Big Bend National Park in September?
- Big Bend National Park has a mean US Air Quality Index of about 38 in September.