Boston climate
Boston (Massachusetts, United States) has a hot-summer humid continental climate (Köppen Dfa). The average temperature over the year is 10 °C50 °F, and about 1,207 mm48 in of precipitation falls in an average year.
Temperature by month
Precipitation by month
Boston climate table
| Month | High °C°F | Low °C°F | Mean °C°F | Precip. mmin | Frost days |
|---|---|---|---|---|---|
| Jan | 134 | −719 | −326 | 803.2 | 28 |
| Feb | 236 | −720 | −228 | 873.4 | 26 |
| Mar | 643 | −327 | 235 | 1104.3 | 24 |
| Apr | 1355 | 337 | 846 | 1074.2 | 9 |
| May | 1966 | 947 | 1457 | 953.7 | 0 |
| Jun | 2475 | 1457 | 1966 | 1134.5 | 0 |
| Jul | 2882 | 1864 | 2373 | 943.7 | 0 |
| Aug | 2882 | 1763 | 2272 | 933.7 | 0 |
| Sep | 2475 | 1355 | 1965 | 923.6 | 0 |
| Oct | 1762 | 745 | 1253 | 1234.8 | 2 |
| Nov | 1050 | 135 | 642 | 983.8 | 12 |
| Dec | 439 | −326 | 033 | 1164.6 | 25 |
| Year | 2882 | −719 | 1050 | 1,20748 | 126 |
“Year” row: highest monthly high, lowest monthly low, annual mean and annual total. Frost days are for the whole grid cell.
| Month | Humid. | Cloud | Solar | Daylight |
|---|---|---|---|---|
| Jan | 88% | 62% | 1.8 | 9:24 |
| Feb | 87% | 61% | 2.7 | 10:30 |
| Mar | 82% | 61% | 3.7 | 11:48 |
| Apr | 79% | 61% | 4.7 | 13:19 |
| May | 79% | 64% | 5.3 | 14:35 |
| Jun | 79% | 62% | 5.7 | 15:16 |
| Jul | 75% | 55% | 6.0 | 14:59 |
| Aug | 73% | 53% | 5.3 | 13:53 |
| Sep | 74% | 51% | 4.3 | 12:25 |
| Oct | 79% | 59% | 2.8 | 10:58 |
| Nov | 82% | 60% | 2.0 | 9:42 |
| Dec | 86% | 63% | 1.5 | 9:05 |
Humid. = average relative humidity at 2 m; cloud = average cloud amount; solar = average daily solar energy reaching the ground in kWh/m² (all-sky); daylight in hours:minutes, calculated for the 15th of each month.
What the climate of Boston is like
The warmest month is July, with an average high of 28 °C82 °F and a low of 18 °C64 °F. The coldest is January, when highs average 1 °C34 °F and lows −7 °C19 °F. Seasons are strongly marked: the warmest month is on average 26 °C46.7 °F warmer than the coldest.
It is wet, with about 1,207 mm48 in of precipitation per year. Rain is spread fairly evenly through the year. The wettest month is October (123 mm4.8 in), the driest is January (80 mm3.2 in).
Relative humidity ranges from 73% in August to 88% in January. The clearest skies (lowest average cloud amount, 51%) are typical of September. Average wind speed near the ground ranges from 1 km/h (1 mph) in July to 4 km/h (3 mph) in February. Daylight lasts from about 9.1 hours in December to 15.3 hours in June.
A lasting snow cover is typical in December–March, when the average snow depth in the reanalysis exceeds 10 cm (deepest in February, about 16 cm).
Best time to visit Boston
Based on these averages, the most comfortable months for sightseeing and outdoor activities are June–September: average highs of 24 °C75 °F to 28 °C82 °F with 92 mm3.6 in to 113 mm4.5 in of precipitation per month.
The most challenging month is January, which is cold, with average highs of 1 °C34 °F.
Comfort score: months are ranked by how close they come to an average high of 21–28 °C (70–82 °F), lows above 5 °C (41 °F), little precipitation and moderate humidity. The best-ranked months of each place are recommended, even where none meets all of these. These are general rules of thumb applied to long-term averages.
What to pack for Boston
- Winter (December–February) — highs 134 to 4 °C39 °F, lows −719 to −3 °C26 °F, about 94 mm3.7 in of precipitation a month. Pack a winter coat, hat, gloves and warm, non-slip boots, shoes with good grip, as frost is common and an umbrella or light rain jacket.
- Spring (March–May) — highs 643 to 19 °C66 °F, lows −327 to 9 °C47 °F, about 104 mm4.1 in of precipitation a month. Pack long sleeves, a sweater and a medium jacket, an extra layer for the cooler mornings and evenings and an umbrella or light rain jacket.
- Summer (June–August) — highs 2475 to 28 °C82 °F, lows 1457 to 18 °C64 °F, about 100 mm3.9 in of precipitation a month. Pack light summer clothes such as T-shirts, shorts or light dresses, an extra layer for the cooler mornings and evenings and an umbrella or light rain jacket.
- Autumn (September–November) — highs 1050 to 24 °C75 °F, lows 135 to 13 °C55 °F, about 104 mm4.1 in of precipitation a month. Pack long sleeves, a sweater and a medium jacket and an umbrella or light rain jacket.
How Boston compares
Compared with Manhattan, about 299 km to the southwest, Boston is on average 1.4 °C2.5 °F cooler and receives a similar amount of precipitation. The difference is largest in June (1.7 °C3.1 °F cooler).
Of the 222 places in the United States covered by World Climates, Boston is the 197th warmest by annual mean temperature and the 67th wettest by annual precipitation. See all of them on the United States climate page.
Places in other countries with the most similar temperature and rainfall pattern: Hirosaki (Japan, Dfa), Morioka (Japan, Dfa) and St. Catharines (Canada, Dfa).
The same NASA POWER grid cell also contains Lowell (pop. 110,699) and Cambridge (pop. 110,402). Their long-term averages in this dataset are essentially the same as for Boston, so they do not have separate pages.
Nearby places
- Worcester 62 km · 9 °C48 °F · 1,183 mm47 in
- Providence 66 km · 11 °C51 °F · 1,208 mm48 in
- Manchester 78 km · 9 °C48 °F · 1,181 mm46 in
- New Bedford 81 km · 11 °C52 °F · 1,155 mm45 in
- Springfield 129 km · 10 °C51 °F · 1,201 mm47 in
- Hartford 150 km · 10 °C51 °F · 1,201 mm47 in
- Waterbury 187 km · 10 °C51 °F · 1,208 mm48 in
- New Haven 194 km · 11 °C52 °F · 1,208 mm48 in
Frequently asked questions
What is the warmest month in Boston?
July is the warmest month in Boston, with an average high of 28 °C (82 °F) and an average low of 18 °C (64 °F).
What is the coldest month in Boston?
January is the coldest month, with an average high of 1 °C (34 °F) and an average low of -7 °C (19 °F).
When does it rain the most in Boston?
October is the wettest month with about 123 mm (4.8 in) of precipitation; January is the driest with about 80 mm (3.2 in).
What is the best time to visit Boston?
Judging by long-term averages, the most comfortable months are June–September.
About this data
All figures are 25-year averages (January 2001 – December 2025) from the NASA POWER project. Temperature, humidity, wind and precipitation come from the MERRA-2 reanalysis (precipitation is the bias-corrected MERRA-2 product), cloud and solar values from CERES satellite data. They describe a grid cell of roughly 50–70 km, not a single weather station, so they can differ from airport records — most of all on coasts, in mountains and for rainfall. Average highs and lows are the monthly mean temperature plus/minus half of the average daily temperature range. Counts of rainy days are not part of this dataset.
The grid cell’s average elevation is 71 m, while Boston lies at about 14 m. Temperatures on this page were therefore adjusted by +0.4 °C0.7 °F using the standard lapse rate of 6.5 °C per 1,000 m.