Boston Climate Records and Averages

Boston is situated on or near several tracks frequently followed by low pressure storm systems. The weather fluctuates regularly from fair to cloudy to stormy conditions and assures an adequate amount of precipitation. Boston's proximity to the Atlantic Ocean produces a moderating influence on temperature extremes of winter and summer.

Hot summer afternoons are frequently relieved by the sea breeze This refreshing east wind is more commonly experienced along the shore than in the interior of the city or the western suburbs. In winter, under appropriate conditions, the severity of cold waves is reduced by the nearness of the relatively warm ocean. The average last occurrence of freezing temperature in spring is early April and the first occurrence of freezing temperature in autumn is early November. In suburban areas, especially away from the coast, these dates are later in spring and earlier in autumn by up to one month in the more susceptible localities.

Coastal storms, or northeasters, are prolific producers of rain and snow. The main snow season extends from December through March. Periods when the ground is bare or nearly bare of snow may occur at any time in the winter. Heavy fog occurs on an average of about two days per month with its prevalence increasing eastward from the interior of Boston Bay to the open waters beyond.

	Monthly Averages			Daily Extremes				Monthly Extremes				Max. Temp.		Min. Temp.
Temperatures in F	Max.	Min.	Avg	High	Date of daily extreme high	Low	Date of daily extreme low	Highest Avg	Year	Lowest Avg	Year	# Days >= 90 F	# Days <= 32 F	# Days <= 32 F	# Days <= 0 F
January	36.4	22.2	29.3	72	26/1950	-12	15/1957	38.8	1932	20.7	2004	0.0	10.5	25.7	0.5
February	38.0	23.3	30.6	70	24/1985	-18	09/1934	38.1	1925	17.5	1934	0.0	7.5	23.4	0.4
March	45.6	30.9	38.2	89	31/1998	1	05/1948	47.2	1946	31.8	1984	0.0	2.2	16.5	0.0
April	56.0	40.1	48.1	94	18/1976	13	01/1923	55.1	1976	43.3	1939	0.1	0.0	2.7	0.0
May	66.7	49.8	58.2	96	30/1929	34	16/1936	63.2	1991	51.6	1967	0.6	0.0	0.0	0.0
June	76.4	59.1	67.7	100	06/1925	41	01/1945	73.3	1976	63.3	1982	2.7	0.0	0.0	0.0
July	81.6	65.0	73.3	103	22/1926	50	01/1988	78.0	1983	69.4	1992	4.9	0.0	0.0	0.0
August	79.8	63.9	71.8	102	02/1975	46	25/1940	75.5	1988	66.4	1964	3.4	0.0	0.0	0.0
September	72.6	56.9	64.7	100	02/1953	37	27/1947	70.6	1983	60.8	1963	0.8	0.0	0.0	0.0
October	62.5	46.7	54.6	90	12/1954	25	27/1936	61.5	1947	49.5	1925	0.0	0.0	0.5	0.0
November	51.7	37.8	44.8	83	02/1950	8	27/1932	51.8	1975	38.3	1933	0.0	0.4	7.4	0.0
December	40.7	27.0	33.8	76	07/1998	-17	29/1933	41.0	2006	21.7	1989	0.0	6.1	21.6	0.2

Annual	59.0	43.5	51.3	103	19260722	-18	1934/02/09	53.6	1949	48.5	1940	12.5	26.7	97.7	1.1

Winter	38.4	24.1	31.3	76	19981207	-18	1934/02/09	37.4	2002	24.7	1934	0.0	24.1	70.6	1.1
Spring	56.1	40.2	48.2	96	19290530	1	1948/03/05	53.2	2010	43.2	1967	0.7	2.2	19.2	0.0
Summer	79.2	62.7	71.0	103	19260722	41	1945/06/01	74.1	1983	68.2	1927	11.0	0.0	0.0	0.0
Fall	62.3	47.1	54.7	100	19530902	8	1932/11/27	58.3	1931	52.2	1967	0.8	0.4	7.9	0.0

												Total Snowfall
	Avg.	High	Year	Low	Year	1 Day Max.		>= 0.01 in.	>= 0.10 in.	>= 0.50 in.	>= 1.00 in.	Mean	High	Year
	in.	in.	-	in.	-	in.	dd/yyyy or yyyymmdd	# Days	# Days	# Days	# Days	in.	in.	-
January	3.61	10.55	1979	0.61	1989	2.52	21/1979	12	7	3	1	12.7	43.3	2005
February	3.33	7.94	2008	0.72	1987	2.66	13/2008	10	6	2	1	12.1	41.3	1969
March	3.99	14.87	2010	0.56	2006	4.00	28/1939	12	7	3	1	7.2	38.9	1993
April	3.66	9.57	2004	0.83	1999	4.29	01/2004	11	7	2	1	0.8	13.3	1982
May	3.33	13.38	1954	0.25	1944	4.47	16/1954	11	7	2	1	0.0	0.9	1938
June	3.38	13.20	1982	0.00	1999	5.69	13/1998	11	6	2	1	-	-	-
July	3.09	11.69	1921	0.52	1952	6.04	09/1921	9	6	2	1	-	-	-
August	3.39	17.09	1955	0.66	2007	7.06	19/1955	10	6	2	1	-	-	-
September	3.26	10.94	1933	0.22	1930	5.63	16/1933	9	5	2	1	-	-	-
October	3.33	10.66	1996	0.06	1924	6.11	20/1996	9	5	2	1	0.0	1.1	2005
November	3.93	8.89	1983	0.64	1976	3.31	23/1992	11	7	3	1	1.2	9.5	1940
December	3.87	9.74	1969	0.66	1935	4.21	12/1992	11	7	3	1	7.7	27.9	1970

Annual	42.16	62.14	1954	23.71	1965	7.06	1955/08/19	125	75	28	10	41.7	98.6	1945

Winter	10.81	21.99	1958	3.04	1980	4.21	1992/12/12	33	20	8	2	32.4	81.5	1994
Spring	10.98	22.10	1953	4.35	1927	4.47	1954/05/16	34	21	7	2	8.1	41.1	1993
Summer	9.86	24.89	1955	3.97	1957	7.06	1955/08/19	30	18	6	2	0.0	-	-
Fall	10.51	18.93	1996	3.36	1946	6.11	1996/10/20	28	17	7	3	1.2	9.5	1940

Winter = Dec, Jan, and Feb		Spring = Mar, Apr, and May
Summer = Jun, Jul, and Aug.		Fall = Sep, Oct, and Nov