Boston MA Average Temperatures by Month

The numbers here tell you how hot and cold the weather usually is in Boston, Massachusetts during each month of the year.

The average high and low temperatures are listed below monthly and annually for Boston, in both degrees Fahrenheit and Celsius.

Maximums and minimums are only part of the temperature picture. To fill in the rest, there's information on how many days a month get above or below a given temperature.

To find out how often it rises over 70, 80 or 90 °F each month in Boston, scroll down farther. There are also monthly and yearly counts of days with cold weather.

The first set of high and low temperatures are averages for 2010 to 2019. Everything else here is based on 1991 to 2020 weather recorded at Boston's Logan International Airport.

10-year temperature averages for Boston, 2010 to 2019
High °F	Low °F		High °C	Low °C
37	23	January	3	-5
40	25	February	4	-4
46	31	March	8	0
58	42	April	14	5
68	52	May	20	11
76	60	June	24	16
84	68	July	29	20
82	66	August	28	19
75	60	September	24	15
64	49	October	18	10
52	38	November	11	3
43	30	December	6	-1
60	45	Year	16	7

30-year temperature averages for Boston, 1991 to 2020
High °F	Low °F		High °C	Low °C
37	23	January	3	-5
39	25	February	4	-4
46	31	March	8	0
56	41	April	14	5
67	50	May	19	10
76	60	June	25	15
82	66	July	28	19
80	65	August	27	18
73	58	September	23	15
62	48	October	17	9
52	38	November	11	3
42	29	December	6	-2
59	45	Year	15	7

Days of Hot Weather in Boston

Boston averages 14 days a year with temperatures into the 90s Fahrenheit. But temperatures of over 100 degrees (38 °C) are uncommon for the city, happening an average of just once a decade.

Most summer days reach at least 70, while nighttime lows are in the 60s. Highs of 70 degrees can occur in Boston any month of the year.

Days per month in Boston of at least 70, 80 or 90 °F
	70 °F 21 °C	80 °F 27 °C	90 °F 32 °C
January	0	0	0
February	0	0	0
March	1	0	0
April	4	1	0
May	12	4	1
June	23	12	3
July	29	20	6
August	29	18	4
September	20	7	1
October	6	1	0
November	1	0	0
December	0	0	0
Year	125	63	14

How Often Boston Has Cold Temperatures

The thermometer on most winter nights in Boston dips to below freezing. Frost can also show up in March, April and November. The city averages one day a year of extreme cold, when the temperature plummets to zero degrees Fahrenheit or less.

Periodically from December to March, Boston's daytime high never makes it above 32 degrees. On average the city gets 23 days a year when the temperature remains below freezing. Crisp days mostly occur in January, but can happen anytime in winter.

Days per month on average in Boston when the minimum temperature drops to 10, 20, or 32 °F or below
	10 °F -12 °C	20 °F -8 °C	32 °F 0 °C
January	4	12	25
February	2	9	22
March	0	3	16
April	0	0	2
May	0	0	0
June	0	0	0
July	0	0	0
August	0	0	0
September	0	0	0
October	0	0	0
November	0	0	7
December	1	5	20
Year	7	29	92

Boston Temperatures: Averages by Month

Days of Hot Weather in Boston

How Often Boston Has Cold Temperatures

References

More on Weather in Massachusetts