Boston weather in May
May in Boston: nice, a little rain, with clean air — one of the best months to visit.
#2 of 12 months in Boston · #128 of 604 destinations to visit in May · comfort 88/100 (tier A)
Updated June 2026 · climate normals from ERA5 reanalysis
Boston climate normals — May
| Daytime high | 19°C / 67°F | 😎 nice |
|---|---|---|
| Nighttime low | 10°C / 50°F | |
| Feels like (high) | 18°C / 64°F | |
| Rainfall | 74 mm / 2.9 in | 🌦 some rain |
| Rainy days | 10 days | |
| Humidity | 67% | 💧 humid |
| Dew point | 8°C / 46°F | |
| Sunshine | 10.5 h/day | |
| Daylight | 14.6 h | |
| Wind | 20 km/h / 12 mph | |
| Air quality (US AQI) | 43 | 🍃 good |
Monthly averages from ERA5 reanalysis. AQI is the mean US Air Quality Index for the month.
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Boston in May — FAQ
- Is May a good time to visit Boston?
- May in Boston: nice, a little rain, with clean air — one of the best months to visit. It ranks #2 of 12 months for Boston on SeasonMap's comfort score (88/100).
- What is the weather like in Boston in May?
- In May, Boston averages a daily high of 19.3°C and a low of 9.8°C, with about 73.9 mm of rain over roughly 9.6 rainy days.
- What is the air quality in Boston in May?
- Boston has a mean US Air Quality Index of about 43 in May.