Gateway Arch National Park weather in December
December in Gateway Arch National Park: cold, a little rain, with clean air — a great time to visit.
#8 of 12 months in Gateway Arch National Park · #247 of 604 destinations to visit in December · comfort 73/100 (tier B)
Updated June 2026 · climate normals from ERA5 reanalysis
Gateway Arch National Park climate normals — December
| Daytime high | 9°C / 49°F | 🧥 cold |
|---|---|---|
| Nighttime low | 1°C / 33°F | |
| Feels like (high) | 6°C / 43°F | |
| Rainfall | 62 mm / 2.4 in | 🌦 some rain |
| Rainy days | 9 days | |
| Humidity | 70% | 💧 humid |
| Dew point | -2°C / 29°F | |
| Sunshine | 5.8 h/day | |
| Daylight | 9.5 h | |
| Wind | 17 km/h / 11 mph | |
| Snowfall | 3.9 cm / 1.5 in | |
| Air quality (US AQI) | 32 | 🍃 good |
Monthly averages from ERA5 reanalysis. AQI is the mean US Air Quality Index for the month.
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Gateway Arch National Park in December — FAQ
- Is December a good time to visit Gateway Arch National Park?
- December in Gateway Arch National Park: cold, a little rain, with clean air — a great time to visit. It ranks #8 of 12 months for Gateway Arch National Park on SeasonMap's comfort score (73/100).
- What is the weather like in Gateway Arch National Park in December?
- In December, Gateway Arch National Park averages a daily high of 9.4°C and a low of 0.8°C, with about 61.6 mm of rain over roughly 9.4 rainy days.
- What is the air quality in Gateway Arch National Park in December?
- Gateway Arch National Park has a mean US Air Quality Index of about 32 in December.
- Does it snow in Gateway Arch National Park in December?
- Gateway Arch National Park sees roughly 3.9 cm of snowfall in December.