Boston weather in August
August in Boston: hot, a little rain — an excellent time to visit.
#4 of 12 months in Boston · #267 of 604 destinations to visit in August · comfort 81/100 (tier A)
Updated June 2026 · climate normals from ERA5 reanalysis
Boston climate normals — August
| Daytime high | 27°C / 81°F | 🥵 hot |
|---|---|---|
| Nighttime low | 19°C / 66°F | |
| Feels like (high) | 29°C / 84°F | |
| Rainfall | 75 mm / 2.9 in | 🌦 some rain |
| Rainy days | 10 days | |
| Humidity | 74% | 💧 humid |
| Dew point | 17°C / 63°F | |
| Sunshine | 10.5 h/day | |
| Daylight | 13.9 h | |
| Wind | 17 km/h / 11 mph | |
| Air quality (US AQI) | 52 | 🙂 moderate |
Monthly averages from ERA5 reanalysis. AQI is the mean US Air Quality Index for the month.
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Boston in August — FAQ
- Is August a good time to visit Boston?
- August in Boston: hot, a little rain — an excellent time to visit. It ranks #4 of 12 months for Boston on SeasonMap's comfort score (81/100).
- What is the weather like in Boston in August?
- In August, Boston averages a daily high of 27.4°C and a low of 19.1°C, with about 74.5 mm of rain over roughly 10.4 rainy days.
- What is the air quality in Boston in August?
- Boston has a mean US Air Quality Index of about 52 in August.