Great Sand Dunes National Park weather in September
September in Great Sand Dunes National Park: nice, dry, with clean air — one of the best months to visit.
#1 of 12 months in Great Sand Dunes National Park · #21 of 604 destinations to visit in September · comfort 93/100 (tier S)
Updated June 2026 · climate normals from ERA5 reanalysis
Great Sand Dunes National Park climate normals — September
| Daytime high | 24°C / 75°F | 😎 nice |
|---|---|---|
| Nighttime low | 10°C / 51°F | |
| Feels like (high) | 21°C / 70°F | |
| Rainfall | 21 mm / 0.8 in | ☀️ dry |
| Rainy days | 4 days | |
| Humidity | 45% | 🍃 comfortable |
| Dew point | 3°C / 37°F | |
| Sunshine | 11.2 h/day | |
| Daylight | 12.4 h | |
| Wind | 14 km/h / 9 mph | |
| Snowfall | 4.6 cm / 1.8 in | |
| 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 Sand Dunes National Park?
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Great Sand Dunes National Park in September — FAQ
- Is September a good time to visit Great Sand Dunes National Park?
- September in Great Sand Dunes National Park: nice, dry, with clean air — one of the best months to visit. It ranks #1 of 12 months for Great Sand Dunes National Park on SeasonMap's comfort score (93/100).
- What is the weather like in Great Sand Dunes National Park in September?
- In September, Great Sand Dunes National Park averages a daily high of 23.9°C and a low of 10.3°C, with about 21.4 mm of rain over roughly 3.6 rainy days.
- What is the air quality in Great Sand Dunes National Park in September?
- Great Sand Dunes National Park has a mean US Air Quality Index of about 37 in September.
- Does it snow in Great Sand Dunes National Park in September?
- Great Sand Dunes National Park sees roughly 4.6 cm of snowfall in September.