Boston has a humid-continental climate softened by the Atlantic, which moderates both summer highs and winter lows compared to inland New England. Nor'easters are the defining weather event, capable of dropping two feet of snow on a single weekend and producing coastal flooding when they align with high tides. Summers are warm and humid but rarely brutal, and sea breezes off Massachusetts Bay can keep the waterfront 10°F cooler than the inland suburbs on hot afternoons. Spring is famously slow to arrive — March is still winter — and fall is the city's most reliably beautiful season.
Climate and Average Weather Year Round in Boston
Year-round temperature
In Boston, the warmest months are June through September, with average daily highs between 73°F and 82°F. The coldest stretch runs December through February, with highs between 37°F and 42°F and overnight lows reaching 23°F.
Rainfall through the year
Rainfall in Boston averages 3.6 in per month over the long run. December is the wettest at 4.3 in, while February is the driest at 3.2 in.
Days at 90 °F or hotter
Boston averages 13.9 days per year at 90 °F or hotter. The hottest year on record saw 27 such days (2002); the coolest just 3 (2026).
Precipitation this year
As of May 28, Boston has received 9.9 in of precipitation this year — 43% below the long-term normal for this point in the year (17.3 in).