Boston, MA Climate & Monthly Averages
The climate of Boston
Boston has a humid subtropical climate, marked by hot, humid summers and generally mild winters. Average daytime highs range from about 37°F (3°C) in January to around 83°F (28°C) in July, and the city records roughly 127 days of measurable precipitation a year.
Climate quick facts
- Hottest month: July - highs near 83°F (28°C)
- Coldest month: January - highs near 37°F (3°C)
- Record high: 101°F (39°C) · Record low: -16°F (-26°C) (2015–2024)
- Wettest month: December (11 rainy days) · Sunniest: July (11.4 h sun/day)
- Climate type: humid subtropical - hot, humid summers and generally mild winters
- Snow: about 16 days a year
Temperatures through the year
The warmest stretch of the year centers on July. Highs average 83°F (28°C) and overnight lows stay near 66°F (19°C). The coolest month is January, with typical highs of 37°F (3°C) and lows around 23°F (-5°C). Based on 2015–2024 weather data, temperatures have reached as high as 101°F (39°C) and dropped as low as -16°F (-26°C).
Rain, sun and snow
December is usually the wettest month. It brings about 4.7 inches (120 mm) of rain over 11 days, while August is the driest. July brings the most sunshine, averaging 11.4 hours of sun a day. Snow falls on about 16 days in a typical year, mostly from December through April.
Monthly climate table
| Month | High | Low | Rain days | Precipitation | Sunshine | Humidity |
|---|---|---|---|---|---|---|
| January | 37° | 23° | 10 | 4.2 in | 6.0 h/day | 67% |
| February | 40° | 22° | 10 | 3.5 in | 6.7 h/day | 69% |
| March | 46° | 29° | 12 | 4.3 in | 7.9 h/day | 67% |
| April | 56° | 39° | 12 | 4.2 in | 8.4 h/day | 69% |
| May | 67° | 49° | 11 | 3.1 in | 10.2 h/day | 70% |
| June | 77° | 59° | 11 | 3.4 in | 11.2 h/day | 71% |
| July | 83° | 66° | 12 | 4.3 in | 11.4 h/day | 72% |
| August | 82° | 65° | 11 | 2.9 in | 10.9 h/day | 73% |
| September | 74° | 59° | 9 | 4.3 in | 8.9 h/day | 75% |
| October | 63° | 48° | 10 | 4.7 in | 7.5 h/day | 76% |
| November | 51° | 36° | 8 | 3.3 in | 6.6 h/day | 71% |
| December | 42° | 28° | 11 | 4.7 in | 5.7 h/day | 73% |
Boston month by month
Boston weather in January
January brings highs around 37°F (3°C), lows near 23°F (-5°C), about 10 wet days and roughly 4 snowy days - typically the coldest month of the year in Boston.
Boston weather in February
February brings highs around 40°F (4°C), lows near 22°F (-6°C), about 10 wet days and roughly 5 snowy days.
Boston weather in March
March brings highs around 46°F (8°C), lows near 29°F (-2°C), about 12 wet days and roughly 3 snowy days.
Boston weather in April
April brings highs around 56°F (13°C), lows near 39°F (4°C), about 12 wet days and roughly 1 snowy days.
Boston weather in May
May brings highs around 67°F (20°C), lows near 49°F (10°C), about 11 wet days.
Boston weather in June
June brings highs around 77°F (25°C), lows near 59°F (15°C), about 11 wet days.
Boston weather in July
July brings highs around 83°F (28°C), lows near 66°F (19°C), about 12 wet days - typically the hottest month and the sunniest month of the year in Boston.
Boston weather in August
August brings highs around 82°F (28°C), lows near 65°F (18°C), about 11 wet days - typically the driest month of the year in Boston.
Boston weather in September
September brings highs around 74°F (23°C), lows near 59°F (15°C), about 9 wet days.
Boston weather in October
October brings highs around 63°F (17°C), lows near 48°F (9°C), about 10 wet days.
Boston weather in November
November brings highs around 51°F (11°C), lows near 36°F (2°C), about 8 wet days.
Boston weather in December
December brings highs around 42°F (6°C), lows near 28°F (-2°C), about 11 wet days and roughly 2 snowy days - typically the wettest month of the year in Boston.
Seasons in Boston
Spring (March through May)
Spring in Boston stays on the cool side of mild, with daytime highs averaging 56°F (13°C) and nights around 39°F (4°C); expect showers on roughly 35 days across the season, plus around 4 snowy days.
Summer (June through August)
Summer in Boston is mild and warm, with daytime highs averaging 81°F (27°C) and nights around 64°F (18°C); expect showers on roughly 34 days across the season.
Fall (September through November)
Fall in Boston is crisp but comfortable, with daytime highs averaging 63°F (17°C) and nights around 48°F (9°C); expect showers on roughly 27 days across the season.
Winter (December through February)
Winter in Boston is chilly, with daytime highs averaging 40°F (4°C) and nights around 24°F (-4°C); expect showers on roughly 31 days across the season, plus around 11 snowy days.
Climate questions, answered
What is the average temperature in Boston?
Is Boston hot in summer?
Is Boston cold in winter?
How many rainy days does Boston get in a year?
Best time to visit Boston
The best time to visit Boston is generally August to October and May to June, when warm days, manageable rainfall and plenty of daylight line up. Daytime temperatures in that window typically sit near 73°F (23°C).
Pack for Boston with a heavy insulated coat, hat and gloves for winter; a compact umbrella or rain shell - showers are a regular feature. Evenings can feel noticeably cooler than afternoons - July nights average 66°F (19°C).
Boston temperature records (2015-2024)
Derived from ERA5 reanalysis data, 2015–2024. Official station records may differ.