Aspen weather in September
September in Aspen: nice, a little rain, with clean air — not the best time to visit.
#10 of 12 months in Aspen · #602 of 604 destinations to visit in September · comfort 22/100 (tier F)
Updated June 2026 · climate normals from ERA5 reanalysis
Aspen climate normals — September
| Daytime high | 22°C / 71°F | 😎 nice |
|---|---|---|
| Nighttime low | 7°C / 44°F | |
| Feels like (high) | 20°C / 68°F | |
| Rainfall | 32 mm / 1.2 in | 🌦 some rain |
| Rainy days | 8 days | |
| Humidity | 55% | 🍃 comfortable |
| Dew point | 4°C / 38°F | |
| Sunshine | 11.2 h/day | |
| Daylight | 12.4 h | |
| Wind | 13 km/h / 8 mph | |
| Snowfall | 2.6 cm / 1 in | |
| 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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Aspen in September — FAQ
- Is September a good time to visit Aspen?
- September in Aspen: nice, a little rain, with clean air — not the best time to visit. It ranks #10 of 12 months for Aspen on SeasonMap's comfort score (22/100).
- What is the weather like in Aspen in September?
- In September, Aspen averages a daily high of 21.8°C and a low of 6.8°C, with about 31.6 mm of rain over roughly 7.8 rainy days.
- What is the air quality in Aspen in September?
- Aspen has a mean US Air Quality Index of about 44 in September.
- Does it snow in Aspen in September?
- Aspen sees roughly 2.6 cm of snowfall in September.