Boston Weather in August
August in Boston brings high temperatures, with daytime highs of 27°C (81°F) and nights around 18°C (64°F). Quite a bit of rainfall is expected, around 95 mm (3.7 in), so pack an umbrella.
Rainfall in Boston in August
On average, there are about 10 days with rain during this month, averaging 95 mm (3.7 in). The rain this month tends to fall in heavier spells rather than light drizzle. When it rains, showers can be significant.
Temperature in Boston in August
August is a perfect month in Boston, with 27°C (81°F) during the day and 18°C (64°F) at night. The summer season takes place during August. Overall, the month follows a fairly predictable daily temperature pattern. Nights cool down to 18°C (64°F), so a light jacket or extra layer is useful once the sun goes down. On the plus side, the cooler nights make for comfortable sleeping conditions.
Sunshine in Boston in August
Expect sunny days throughout the month, with an estimated 280 hours of sunshine. This makes it a pleasant time to visit Boston.
Wind Speed in Boston in August
Wind speeds average 5 m/s (10 knots) during August. At this speed, gentle to moderate breezes make small trees sway and the wind creates whitecaps on water bodies. Daily variations range from moderate winds to stronger breezes, creating excellent conditions for sailing, kite flying and wind sports.
Average water temperature in August
With water at 20°C (68°F), conditions are good for swimming and other water activities. You won't need a wetsuit and most people find it very comfortable.If you're a fan of comfortable temperatures and drier conditions, August is a great time to visit.
Check the conditions for any month of the year.
For a detailed overview over the year and the best time to visit the United States of America, check out our Boston's climate page.
Boston Temperature in August
Min Temperature
18°C (64°F)
Max Temperature
27°C (81°F)
Water Temperature
20°C (68°F)
Chance of Rain
33%
Precipitation
95 mm (3.7 in)
Rainy days
10 days
Humidity
72%
Windspeed
5 m/s (10 knots)
Sunshine
280 hours
Percentage Sunshine
64%
Daily Historical Temperatures
50-year average (1976-2025)
Based on our historical records, temperatures in Boston typically stay consistent throughout August, with daily highs averaging around 27°C (81°F). Nights are pleasant, with lows typically ranging from 17°C (63°F) to 20°C (68°F).
Average temperatures in August
Daily Historical Precipitation
50-year average (1976-2025)
Average daily rainfall for each day of the month based on long-term records.
Average precipitation in August
Historical weather for Boston in August
Browse day-by-day weather records for Boston spanning 51 years. Select any month and year to see actual temperatures, rainfall, and conditions recorded on each day.
Boston historical weather extremes in August
Based on 49 years of weather observations (1976-2025), these are the most extreme conditions recorded in Boston.
- Boston recorded its highest August temperature of 38°C (100°F) on August 14, 2002.
- The lowest daytime temperature in August was 16°C (61°F), recorded on August 29, 1987.
- Boston registered its coldest August night on August 29, 1986, with temperatures dropping to 8°C (46°F).
Best Places in the United States of America in August
Find out more about the weather in the United States of America and which places have the best travel conditions in this month. See all of the United States of America in August →
perfect weather
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What to Wear in Boston in August
Warm but pleasant conditions in Boston in August. Focus on lightweight, maybe with natural fabrics, cotton blend shirts, comfortable shorts, and breathable footwear. A light cover-up for sun protection is smart too. Expect heavy rainfall, so bring good rain protection and waterproof bags. With water temperatures around 20°C (68°F), swimming conditions are excellent. Pack your swimsuit, goggles, and maybe some water shoes. Don't forget sun protection, sunglasses, sunscreen, and a hat. These are all good ideas with this much sunshine.What To Do in Boston in August
We rated the following activities from 1 (least suitable) to 10 (best) to do.
Check the conditions for any month of the year.
For a detailed overview over the year and the best time to visit the United States of America, check out our Boston's climate page.
Temperature Rainfall Sunshine Humidity Wind Speed Water Temp
See the full Boston climate overview or explore weather in the United States of America.
