Boise weather in May
May in Boise: nice, a little rain, with clean air — an excellent time to visit.
#3 of 12 months in Boise · #56 of 604 destinations to visit in May · comfort 91/100 (tier S)
Updated June 2026 · climate normals from ERA5 reanalysis
Boise climate normals — May
| Daytime high | 23°C / 73°F | 😎 nice |
|---|---|---|
| Nighttime low | 9°C / 48°F | |
| Feels like (high) | 20°C / 68°F | |
| Rainfall | 41 mm / 1.6 in | 🌦 some rain |
| Rainy days | 8 days | |
| Humidity | 54% | 🍃 comfortable |
| Dew point | 5°C / 40°F | |
| Sunshine | 12.2 h/day | |
| Daylight | 14.7 h | |
| Wind | 20 km/h / 12 mph | |
| Snowfall | 1.1 cm / 0.4 in | |
| Air quality (US AQI) | 42 | 🍃 good |
Monthly averages from ERA5 reanalysis. AQI is the mean US Air Quality Index for the month.
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Boise in May — FAQ
- Is May a good time to visit Boise?
- May in Boise: nice, a little rain, with clean air — an excellent time to visit. It ranks #3 of 12 months for Boise on SeasonMap's comfort score (91/100).
- What is the weather like in Boise in May?
- In May, Boise averages a daily high of 22.5°C and a low of 8.7°C, with about 41.4 mm of rain over roughly 8.2 rainy days.
- What is the air quality in Boise in May?
- Boise has a mean US Air Quality Index of about 42 in May.
- Does it snow in Boise in May?
- Boise sees roughly 1.1 cm of snowfall in May.