Great Smoky Mountains National Park weather in September
September in Great Smoky Mountains National Park: warm, rainy, with clean air — an excellent time to visit.
#5 of 12 months in Great Smoky Mountains National Park · #218 of 604 destinations to visit in September · comfort 84/100 (tier A)
Updated June 2026 · climate normals from ERA5 reanalysis
Great Smoky Mountains National Park climate normals — September
| Daytime high | 23°C / 73°F | 🌤 warm |
|---|---|---|
| Nighttime low | 13°C / 56°F | |
| Feels like (high) | 24°C / 75°F | |
| Rainfall | 102 mm / 4 in | 🌧 rainy |
| Rainy days | 12 days | |
| Humidity | 77% | 💦 very humid |
| Dew point | 13°C / 55°F | |
| Sunshine | 9.9 h/day | |
| Daylight | 12.4 h | |
| Wind | 9 km/h / 5 mph | |
| Air quality (US AQI) | 37 | 🍃 good |
Monthly averages from ERA5 reanalysis. AQI is the mean US Air Quality Index for the month.
Where is Great Smoky Mountains National Park?
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Great Smoky Mountains National Park in September — FAQ
- Is September a good time to visit Great Smoky Mountains National Park?
- September in Great Smoky Mountains National Park: warm, rainy, with clean air — an excellent time to visit. It ranks #5 of 12 months for Great Smoky Mountains National Park on SeasonMap's comfort score (84/100).
- What is the weather like in Great Smoky Mountains National Park in September?
- In September, Great Smoky Mountains National Park averages a daily high of 22.7°C and a low of 13.4°C, with about 102 mm of rain over roughly 11.6 rainy days.
- What is the air quality in Great Smoky Mountains National Park in September?
- Great Smoky Mountains National Park has a mean US Air Quality Index of about 37 in September.