Gateway Arch National Park weather in May
May in Gateway Arch National Park: warm, rainy — an excellent time to visit.
#4 of 12 months in Gateway Arch National Park · #314 of 604 destinations to visit in May · comfort 81/100 (tier A)
Updated June 2026 · climate normals from ERA5 reanalysis
Gateway Arch National Park climate normals — May
| Daytime high | 24°C / 76°F | 🌤 warm |
|---|---|---|
| Nighttime low | 14°C / 58°F | |
| Feels like (high) | 25°C / 77°F | |
| Rainfall | 132 mm / 5.2 in | 🌧 rainy |
| Rainy days | 14 days | |
| Humidity | 66% | 💧 humid |
| Dew point | 13°C / 55°F | |
| Sunshine | 9.6 h/day | |
| Daylight | 14.3 h | |
| Wind | 17 km/h / 11 mph | |
| Air quality (US AQI) | 53 | 🙂 moderate |
Monthly averages from ERA5 reanalysis. AQI is the mean US Air Quality Index for the month.
Where is Gateway Arch National Park?
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Gateway Arch National Park in May — FAQ
- Is May a good time to visit Gateway Arch National Park?
- May in Gateway Arch National Park: warm, rainy — an excellent time to visit. It ranks #4 of 12 months for Gateway Arch National Park on SeasonMap's comfort score (81/100).
- What is the weather like in Gateway Arch National Park in May?
- In May, Gateway Arch National Park averages a daily high of 24.3°C and a low of 14.4°C, with about 132.1 mm of rain over roughly 14 rainy days.
- What is the air quality in Gateway Arch National Park in May?
- Gateway Arch National Park has a mean US Air Quality Index of about 53 in May.