Arches National Park weather in September
September in Arches National Park: warm, dry, with clean air — an excellent time to visit.
#4 of 12 months in Arches National Park · #157 of 604 destinations to visit in September · comfort 86/100 (tier A)
Updated June 2026 · climate normals from ERA5 reanalysis
Arches National Park climate normals — September
| Daytime high | 29°C / 84°F | 🌤 warm |
|---|---|---|
| Nighttime low | 14°C / 57°F | |
| Feels like (high) | 26°C / 79°F | |
| Rainfall | 14 mm / 0.6 in | ☀️ dry |
| Rainy days | 3 days | |
| Humidity | 31% | 🌵 dry |
| Dew point | 1°C / 34°F | |
| Sunshine | 11.3 h/day | |
| Daylight | 12.4 h | |
| Wind | 16 km/h / 10 mph | |
| Air quality (US AQI) | 39 | 🍃 good |
Monthly averages from ERA5 reanalysis. AQI is the mean US Air Quality Index for the month.
Where is Arches National Park?
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Arches National Park in September — FAQ
- Is September a good time to visit Arches National Park?
- September in Arches National Park: warm, dry, with clean air — an excellent time to visit. It ranks #4 of 12 months for Arches National Park on SeasonMap's comfort score (86/100).
- What is the weather like in Arches National Park in September?
- In September, Arches National Park averages a daily high of 29°C and a low of 14°C, with about 14 mm of rain over roughly 2.8 rainy days.
- What is the air quality in Arches National Park in September?
- Arches National Park has a mean US Air Quality Index of about 39 in September.