Weather in Boston in August 2025
Average weather
Average temperature in Boston in August
The temperature in August is +26°C on average, with a range between a maximum of +30°C during the day and a minimum of +14°C at night.
The average maximum temperature goes down 12% by the end of the month, compared with the beginning of the month, from +25°C to +23°C.
Is Boston warm or cold in August?
Boston is typically warm in August.
Maximum temperatures go down compared to the previous month from +27°C to +26°C. The minimum temperature also goes down from +19°C to +18°C.
It’s generally warm, but pack a long-sleeve shirt for evenings.
August is one of the warmest months in Boston, here is the comparison with other months:
Water temperature in Boston in August
Water in Boston in August is Fresh. It varies from +18°C to +21°C, with an average of +20°C. The air temperature averaging +26°C is higher than the water temperature.
The water temperature in August is one of the warmest of the entire year:
Can you swim in Boston in August?
Climate in Boston in August
| July | August | September | ||||
|---|---|---|---|---|---|---|
| Avg. temperature | ||||||
| +27°C | +26°C | +22°C | ||||
| Min. temperature | ||||||
| +10°C | +8°C | +3°C | ||||
| Max. temperature | ||||||
| +38°C | +36°C | +35°C | ||||
| Rainfall | ||||||
| 114 mm | 111 mm | 98 mm | ||||
| Wind | ||||||
| 3 m/s | 3 m/s | 3 m/s | ||||
| Avg. water temperature | ||||||
| +19°C | +20°C | +18°C | ||||
| Humidity | ||||||
| 69% | 70% | 72% | ||||
| Air pressure | ||||||
| 1013 HPa | 1015 HPa | 1017 HPa | ||||
| Sunny days | ||||||
| 3 | 5 | 7 | ||||
| Cloudy days | ||||||
| 11 | 10 | 10 | ||||
| Rainy days | ||||||
| 14 | 14 | 12 | ||||
| Snowy days | ||||||
| 0 | 0 | 0 | ||||
August weather is still as good as in July. It’s getting colder in August. From +27°C in the day, the average maximum temperature lowers to +26°C. As August arrives, the amount of rainfall goes down. On average, the rainfall volume decreases from 114 mm to 111 mm. Humidity rises from 69% to 70%. The average wind speed doesn’t change much during August, staying around 3 m/s. The good news is there are likely to be more sunny days in August, from 3 to 5.
September brings much the same weather, it remains good.
Wind
The average wind speed is 3 m/s getting up to 6 m/s which is a medium breeze. You can feel it, especially getting out of the water.
The average wind speed in Boston is gradually increasing during August, going from 3 m/s to 4 m/s over the course of the month.
Rain
How was the weather last August in Boston?
Climate Change over Years
The climate in Boston in August has not changed much over the last 43 years.
The average temperature was the lowest in 1992 (+14°C) and the highest in 2022 (+17°C). The driest year was 2016 with only 702 mm of rainfall, and the wettest year was 2021 with 2022 mm.
FAQ
Is August a good time to visit Boston?
Can you sunbathe in Boston in August?
Can you swim in Boston in August?
Is Boston rainy in August?
Is it sunny in Boston in August?
Other cities in USA
Monthly weather in Boston
Source of the data
For this page, we’ve looked at the typical weather in Boston, based on historical hourly weather data from January 1, 1979, to December 31, 2023.
For past dates, we show actual recorded data at the location at that time. Forecasts are based on recorded weather during that day of the year, averaged over the total years for which we have records (unless stated otherwise). The daily temperature is the highest recorded temperature in the shadow during that day.