Boston has chilly winters and warm summers
A typical July afternoon reaches 85°, a January night drops to 22°, and about 21 inches of snow falls in a normal winter.
A year in Boston at a glance
Each month’s typical high and low, and what it brings.
What stands out about Boston’s climate
Read from where Boston sits among Pennsylvania’s towns. The page puts what stands out first.
21 inches of snow, 42 of rain and melt
June is the wettest month and February the driest. Rain or snow falls on about 147 days a year.
Rain + melted snow by month
Inches of water
Snowfall by month
Inches of snow
What a year in Boston feels like
Typical highs and lows by season and by month, from NOAA’s 30-year normals.
Warmer than it used to be
The last 30 years in Boston averaged 0.9° warmer than the 1900s. The biggest change is in December (+2.1°).
A smaller shift than in 76% of U.S. towns.
Change by month
About 170 frost-free days a year
In half of years the last 32° night comes by May 2 and the first by October 20.
Freezing nights by month
Average nights at or below 32°
90° days by month
Average days at 90° or more
Living with Boston’s climate
What the numbers mean for a garden, a driveway, a furnace and a free afternoon.
170 frost-free days. The last frost comes by May 2 in half of years, so many gardeners wait a week or two past that to set out tomatoes. The first fall frost comes by Oct 20.
About 21" a winter over 8 days with an inch or more, most in February. Snow covers the ground about 24 days a year.
Months averaging under 55° run from October through April. Heating is 88% of the year’s heating-and-cooling load.
About 14 days a year reach 90°, and July afternoons average 85°.
The nicest months are May, June, August, September and October.
Parks & trails →Normals are averages. Ice storms, nor’easters, floods and heat waves are on the natural hazards page.
Natural hazards →Boston and its neighbors
Elizabeth has the coldest January nights next door (22°) and Versailles the hottest July afternoons (85°). Tap a town to see its climate.
Temperatures and rain come from NOAA’s 5 km grid, so each town gets its own value. Snow and frost-free days come from the nearest weather station, so neighbors often share them.
How Boston compares
Against every U.S. town on TownTapestry, each counted once, with its place in Pennsylvania.
Boston weather by month
Average highs, lows, rain and snow for every month, from NOAA’s 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | Snow on ground | 30-yr range |
|---|---|---|---|---|---|---|---|
| January | 38° | 22° | 3.0" | 5.7" | 15 | 9 | 22° – 40° |
| February | 42° | 23° | 2.6" | 7.2" | 12 | 7 | 20° – 41° |
| March | 51° | 30° | 3.3" | 4.6" | 13 | 3 | 34° – 52° |
| April | 64° | 40° | 3.5" | 0.1" | 14 | 0 | 46° – 56° |
| May | 73° | 49° | 4.0" | 0 | 14 | 0 | 54° – 68° |
| June | 81° | 58° | 4.5" | 0 | 13 | 0 | 65° – 72° |
| July | 85° | 62° | 4.3" | 0 | 11 | 0 | 69° – 78° |
| August | 83° | 61° | 3.8" | 0 | 10 | 0 | 68° – 77° |
| September | 77° | 54° | 3.5" | 0 | 10 | 0 | 62° – 70° |
| October | 65° | 43° | 3.0" | 0 | 12 | 0 | 51° – 60° |
| November | 53° | 34° | 3.0" | 0.5" | 12 | 1 | 37° – 48° |
| December | 42° | 27° | 3.1" | 3.3" | 13 | 5 | 25° – 45° |
| Year | 63° | 42° | 41.6" | 21.4" | 147 | 24 |
Heating and cooling a home in Boston
88% of the work is heating, so the furnace matters far more than the air conditioner.
Degree days add up how far each day’s average falls below (heating) or rises above (cooling) 65° over a year. Source: NOAA station normals.
How much a month can swing
A normal is an average. February swings the most: from 1991 to 2020 its average ranged from 20° to 41°. June is the most reliable, staying within 6°.
Common questions about Boston’s climate
What is the coldest month in Boston?
January, with a typical high of 38° and a low of 22°.
What is the hottest month in Boston?
July, with a typical high of 85° and a low of 62°. About 14 days a year reach 90°.
How much snow does Boston get?
About 21 inches in a normal winter, most of it in February.
When is the first frost in Boston?
In half of years the first 32° night comes by October 20, and the last spring frost by May 2.
What is the rainiest month in Boston?
June, with 4.5 inches of rain and melted snow. The year totals 42 inches.
Neighbors talk weather
Gardens, snow, and the best days of the year in Boston.
Your answer becomes a post in Town Square.
Temperatures and rainfall come from NOAA’s gridded climate normals for Boston itself (about a 3-mile square). Snow, frost dates and day counts come from NOAA’s weather station at Donora 1 Sw, PA (10 mi, snow) and Mckeesport, PA (3 mi, frost, heat and degree days). Normals are 30-year averages, not a forecast. Source: NOAA NCEI U.S. Climate Normals, 1991–2020 and 1901–2000. Today’s forecast: National Weather Service.