Boston has chilly, snowy winters and pleasant summers, with plenty of rain. A typical July afternoon reaches 82°, a January night drops to 21°, and about 49 inches of snow falls in a normal winter.
NOAA 1991-2020 climate normalsUpdated once a decade
☀️
July high
82°
252nd hottest of 541 Massachusetts towns
❄️
January low
21°
118th mildest of 541 Massachusetts towns
💧
Rain + melted snow
48 in
268th wettest of 541 Massachusetts towns
🌨️
Snow a winter
49 in
267th least snowy of 534 Massachusetts towns
A normal year
What a year in Boston feels like
❄️
Winter
40° / 23°
Typical high / low · 11 days with an inch or more of snow
🌷
Spring
57° / 39°
Typical high / low · Last frost around Apr 4
☀️
Summer
80° / 61°
Typical high / low · 14 days reach 90° in a normal year
🍂
Fall
63° / 45°
Typical high / low · First frost around Nov 9
10°
20°
40°
50°
60°
70°
80°
90°
100°
32°
37°
21°
39°
22°
46°
29°
57°
39°
67°
48°
77°
58°
82°
64°
81°
63°
74°
55°
62°
44°
52°
35°
42°
27°
JanJFebFMarMAprAMayMJunJJulJAugASepSOctONovNDecD
32°, freezingBar runs from the typical overnight low up to the afternoon high
Best months to be outsideMayJunJulAugSepOctHighs of 62–84° and lows of 40° or more
Month by month
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
30-yr range
January
37°
21°
3.8"
14.3"
12
20° – 36°
February
39°
22°
3.6"
14.4"
11
18° – 37°
March
46°
29°
4.7"
9.0"
12
32° – 46°
April
57°
39°
4.2"
1.6"
12
44° – 52°
May
67°
48°
3.6"
0
12
52° – 63°
June
77°
58°
4.1"
0
11
63° – 70°
July
82°
64°
3.5"
0
9
68° – 77°
August
81°
63°
3.5"
0
9
68° – 76°
September
74°
55°
3.8"
0
9
61° – 68°
October
62°
44°
4.7"
0.2"
11
50° – 60°
November
52°
35°
4.0"
0.7"
10
39° – 49°
December
42°
27°
4.8"
9.0"
12
28° – 44°
Year
60°
42°
48.3"
49.2"
128
“Wet days” have at least 0.01" of rain or melted snow. “Snow on ground” counts days with 1" or more. The 30-year range is the coldest and warmest that month’s average temperature got between 1991 and 2020.
Rain & snow
Rain and snow in Boston
Boston gets 48 inches of rain and melted snow a year. December is the wettest month and July the driest. Rain or snow falls on about 128 days a year.
💧
48 in
Rain + melted snow a year
More rain than 83% of U.S. towns
❄️
49 in
Snow in a normal winter
More snow than 82% of U.S. towns
☔
128 days
With rain or snow (0.01"+)
Rain + melted snow by month
Inches of water
4.8"
JFMAMJJASOND
Snowfall by month
Inches of snow
14"
JFMAMJJASOND
Frost & the growing season
About 218 frost-free days a year
In half of years the last 32° night comes by April 4 and the first one by November 9. That leaves about 218 frost-free days for gardens, longer than 81% of U.S. towns.
🌱 Apr 4
🍂 Nov 9
218 frost-free days
JFMAMJJASOND
🥶
92
nights at or below 32° in a normal year
🧊
<1
nights below 0° in a normal year
🔥
14
days that reach 90° in a normal year
Freezing nights by month
Average nights at or below 32°
JFMAMJJASOND
90° days by month
Average days at 90° or more
JFMAMJJASOND
Heating & cooling
Heating and cooling a home in Boston
Engineers use “degree days” to estimate how hard a furnace or air conditioner works. In Boston, 87% of that work is heating and 13% is cooling, so the furnace matters far more than the air conditioner.
🔥
5,545 heating degree daysLess heating than 55% of U.S. towns
❄️
802 cooling degree daysLess cooling than 53% of U.S. towns
Degree days measure how far each day’s average temperature falls below or rises above 65°, added up over a year. Source: NOAA station normals.
Around Boston
Boston and its neighbors
Boston borders 12 towns with climate data. January nights across them vary by 3.0°. Newton has both the coldest January nights (18°) and the hottest July afternoons (84°). Boston’s January low is 21° and its July high 82°.
Compared with every U.S. town and city on TownTapestry, each counted once.
Then and now
Warmer than it used to be
+2.1°1991–2020 average vs. the 20th century (1901–2000)
The last 30 years in Boston averaged 2.1° warmer than the 1900s. The biggest change is in December (+3.6°). The shift is larger than in 96% of U.S. towns.
❄️ Winter+3.0°now 31°, was 28°
🌷 Spring+1.6°now 48°, was 46°
☀️ Summer+2.2°now 71°, was 68°
🍂 Fall+1.8°now 54°, was 52°
Change by month1991–2020 average minus 1901–2000 average, at Boston’s spot on NOAA’s grid
+1.1°
+3.6°
JanJFebFMarMAprAMayMJunJJulJAugASepSOctONovNDecD
Year to year
How much a month can swing
A normal is an average, and real years wander around it. February swings the most: between 1991 and 2020 its average temperature ranged from 18° to 37°. June is the most reliable, staying within 7°.
10°
20°
30°
40°
50°
60°
70°
80°
90°
JanJFebFMarMAprAMayMJunJJulJAugASepSOctONovNDecD
Coldest to warmest month in 30 yearsNormal
Questions
Common questions about Boston’s climate
What is the coldest month in Boston?
January, with a typical high of 37° and a low of 21°.
What is the hottest month in Boston?
July, with a typical high of 82° and a low of 64°. About 14 days a year reach 90°.
How much snow does Boston get?
About 49 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 November 9, and the last spring frost by April 4.
What is the rainiest month in Boston?
December, with 4.8 inches of rain and melted snow. The year totals 48 inches.
📍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 Boston Logan Intl Airport, MA (2 mi) away. Normals are 30-year averages, not a forecast. Source: NOAA NCEI U.S. Climate Normals, 1991–2020 and 1901–2000.