Boston month by month
Plan your visit to Boston by month. Compare weather, crowds, events, and prices across all twelve months with historical climate data.
Boston's measured year covers a 26-degree swing, from a January average high of 3°C to 29°C in July. That range draws four distinct bands. December through February holds steady between 3°C and 6°C. Spring moves fast. March sits at 9°C, April reaches 14°C, and by May the average high hits 20°C. Summer levels off across June, July, and August at 26°C to 29°C. Autumn pulls back through September's 23°C, October's 18°C, and November's 11°C.
Rain days stay within a narrow band all year, from 7 in November to 13 in July. Temperature is the real variable across the 12 month pages below. If you're planning around warm weather, open June, July, or August first. October pairs 18°C highs with only 8 rain days, the strongest balance in the full year. The spring pages, March through May, track the steepest climb in the data, 11 degrees across 2 months, so shifting travel dates by a few weeks changes outdoor conditions considerably.
July leads the year at 29°C but also records 13 rain days, more than any other month. November logs the fewest at 7, though highs have already dropped to 11°C.
October averages 18°C with only 8 rain days, the driest month in Boston's warm half of the year.
- January
- High
- 3°C
- Low
- -5°C
- Rain
- 113 mm
January in Boston is cold. Not the mild, damp cold of London or Seattle, but a sharp, dry cold that stings exposed skin within minutes of stepping outside. Average highs hover…
- February
- High
- 4°C
- Low
- -6°C
- Rain
- 77 mm
February is the coldest month of the year in Boston, and you should know that before anything else. Average highs hover around 4°C (39°F) with lows dropping to -5.6°C (22°F), and…
- March
- High
- 9°C
- Low
- -1°C
- Rain
- 113 mm
March in Boston is still winter. That's the first thing to understand. Daytime highs average 9.3°C (49°F), overnight lows drop to -0.7°C (31°F), and a nor'easter can bury the city…
- April
- High
- 14°C
- Low
- 4°C
- Rain
- 86 mm
April in Boston belongs to one event. The Boston Marathon, held on the third Monday of the month (Patriots' Day, a Massachusetts state holiday), reshapes the entire city for a…
- May
- High
- 20°C
- Low
- 10°C
- Rain
- 111 mm
May is graduation month in Boston, and that single fact likely shapes your entire visit. Harvard, MIT, Boston University, Northeastern, and roughly a dozen other schools release an…
- June
- High
- 26°C
- Low
- 16°C
- Rain
- 77 mm
June is likely the single best month to be in Boston. Daytime temperatures settle around 25.6°C (78°F), lows hover near 15.5°C (60°F), and by the summer solstice on June 21 you're…
- July
- High
- 29°C
- Low
- 19°C
- Rain
- 134 mm
July is Boston's biggest month, and the reason is the 4th. The city where the American Revolution started treats Independence Day like a birthright, and the Boston Pops Fireworks…
- August
- High
- 27°C
- Low
- 18°C
- Rain
- 89 mm
August in Boston means humidity. That is the single defining fact of the month. Temperatures tend to hover around 27°C (81°F) during the day, which sounds manageable on paper, but…
- September
- High
- 23°C
- Low
- 15°C
- Rain
- 129 mm
September is, to be fair, one of the finest months to be in Boston. The single most important thing to know is that roughly 250,000 university students flood back into the city…
- October
- High
- 18°C
- Low
- 9°C
- Rain
- 110 mm
October is likely Boston's single best month. The city's maples and oaks turn deep crimson and burnt orange, and the color tends to start in outer neighborhoods like Jamaica Plain…
- November
- High
- 11°C
- Low
- 2°C
- Rain
- 65 mm
November in Boston is cold, gray, and honest about it. Daytime temperatures hover around 10.9°C (52°F), dropping to 2.4°C (36°F) after dark, and the last of the fall color has…
- December
- High
- 6°C
- Low
- -2°C
- Rain
- 111 mm
December in Boston means early darkness and genuine cold. The sun drops below the horizon before 4:15 PM for most of the month. Daytime temperatures average 5.5°C (42°F) and fall…