Boston weather by month & the best time to visit
United States · major city break · hot-summer continental climate
The best time to visit Boston is July — its sunniest month (Sunshine Score 74/100), with August and September close behind. Boston averages about 2,157 hours of sunshine a year. Daytime highs around 28°C / 82°F and roughly 94 mm of rain in July.
When is the best time to visit Boston?
For sunshine, the best time to visit Boston is July, then August and September. The dullest month is January (0/100, 80 mm of rain). The full month-by-month picture is in the table below.
How sunny is Boston?
Boston gets a moderate 2,157 hours of sunshine a year. 74 Sunshine Score points separate July (74) from January (0), so the month you pick matters. It ranks #338 of 580 destinations in United States for annual sunshine, below the national median of 2,279 hours. The year's 1,207 mm of rain spreads fairly evenly across the months, with no pronounced dry season.
Sunshine Score by month
| Month | Score | Day high | Night low | Rain | UV | Sea |
|---|---|---|---|---|---|---|
| January | 0 | 1° / 34°F | -7° / 19°F | 80 mm | 1 | 4° / 39°F |
| February | 0 | 2° / 36°F | -6° / 21°F | 86 mm | 2 | 4° / 39°F |
| March | 0 | 6° / 43°F | -3° / 27°F | 110 mm | 3 | 5° / 41°F |
| April | 30 | 13° / 55°F | 3° / 37°F | 107 mm | 4 | 8° / 46°F |
| May | 68 | 19° / 66°F | 9° / 48°F | 95 mm | 6 | 13° / 55°F |
| June | 71 | 24° / 75°F | 14° / 57°F | 113 mm | 6 | 18° / 64°F |
| July | 74 | 28° / 82°F | 18° / 64°F | 94 mm | 7 | 19° / 66°F |
| August | 74 | 28° / 82°F | 17° / 63°F | 93 mm | 6 | 20° / 68°F |
| September | 74 | 24° / 75°F | 13° / 55°F | 92 mm | 5 | 19° / 66°F |
| October | 52 | 17° / 63°F | 7° / 45°F | 123 mm | 3 | 15° / 59°F |
| November | 12 | 10° / 50°F | 1° / 34°F | 98 mm | 2 | 10° / 50°F |
| December | 0 | 4° / 39°F | -3° / 27°F | 116 mm | 1 | 6° / 43°F |
Sea temperature in Boston by month
The sea off Boston is warmest in August at around 20°C / 68°F, and coolest in January at 4°C / 39°F. It never reaches comfortable swimming temperatures (21°C+). Month-by-month sea-surface temperatures are in the Sea column of the table above.
Nearest destinations
Head-to-head
How Boston compares month by month: Boston vs Providence/Warwick · Boston vs Manchester (New Hampshire) · Boston vs Portland (Maine) · Boston vs Martha's Vineyard · all comparisons
Boston: questions and answers
What kind of destination is Boston?
Boston is a major city break in United States with a hot-summer continental climate — the sea reaches 20°C at its warmest.
How many hours of sunshine does Boston get a year?
Boston gets about 2,157 hours of sunshine a year, at its best around July.
When is the best time to visit Boston?
The sunniest time to visit Boston is July, when the Sunshine Score peaks at 74/100 (with August and September close behind). Expect daytime highs around 28°C / 82°F.
What is the least sunny month in Boston?
January is the least sunny month in Boston, scoring 0/100 with about 80 mm of rain.
What is the sea temperature in Boston?
The sea in Boston ranges from about 4°C (January) to 20°C (August). Month-by-month sea temperatures are on this page.
How strong is the sun in Boston?
The typical midday UV index in Boston peaks around 7 (high) in July, easing to about 1 (low) in January. Month-by-month midday UV values are in the UV column of the table on this page.
Put the Boston sunshine badge on your site
A compact badge showing Boston's sunshine at a glance — free to embed under CC BY 4.0. Paste this wherever you'd like it to appear:
Live preview — this is exactly what your readers see: