Philadelphia Climate Records and Averages

The Appalachian Mountains to the west and the Atlantic Ocean to the east have a moderating effect on the climate of Philadelphia, Pennsylvania. Periods of very high or very low temperatures rarely last for more than three or four days. Temperatures below zero or above 100 degrees are a rarity. On occasion, the area becomes engulfed with maritime air during the summer months, and high humidity adds to the discomfort of seasonably warm temperatures.

Precipitation is fairly evenly distributed throughout the year with maximum amounts during the late summer months. Much of the summer rainfall is from local thunderstorms and amounts vary in different areas of the city, which is in part due to higher elevations to the west and north. Snowfall amounts are often considerably larger in the northern suburbs than in the central and southern parts of Philadelphia. In many cases, the precipitation will change from snow to rain within the city. Single storms of 10 inches or more occur about every five years.

	Monthly Averages			Daily Extremes				Monthly Extremes
Temperatures in F	Max.	Min.	Avg	High	Date of daily extreme high	Low	Date of daily extreme low	Highest Avg	Year	Lowest Avg	Year
January	39.8	25.0	32.4	74	26/1950	-7	17/1982	43.3	1950	20.0	1977
February	42.5	26.4	34.5	74	15/1949	-4	02/1961	41.8	1998	23.0	1979
March	51.6	33.7	42.6	86	30/1998	7	10/1984	48.8	1977	32.6	1960
April	63.5	43.3	53.4	95	17/2002	19	07/1982	59.4	1994	47.8	1966
May	73.4	53.2	63.3	97	30/1991	28	11/1966	70.8	1991	55.9	1967
June	82.2	62.6	72.4	100	26/1952	44	09/1957	78.2	2010	67.8	1958
July	86.6	68.0	77.3	104	03/1966	51	21/1966	82.1	1994	72.0	1962
August	84.9	66.9	75.9	101	31/1953	44	29/1986	79.9	1980	71.2	1963
September	77.8	59.4	68.6	100	02/1953	35	25/1963	73.8	2005	62.8	1963
October	66.6	47.6	57.1	89	05/1951	25	25/1962	64.5	2007	51.8	1988
November	55.3	38.2	46.8	84	01/1950	15	29/1955	52.9	2001	39.9	1976
December	44.0	29.1	36.6	73	04/1998	1	25/1980	43.7	2001	25.5	1989

Annual	64.0	46.1	55.1	104	1966/07/03	-7	1982/01/17	58.1	1998	51.9	1963

Winter	42.1	26.8	34.5	74	1949/02/15	-7	1982/01/17	41.3	2002	27.9	1977
Spring	62.8	43.4	53.1	97	1991/05/30	7	1984/03/10	58.1	2010	48.6	1984
Summer	84.6	65.8	75.2	104	1966/07/03	44	1957/06/09	79.6	2010	71.9	1962
Fall	66.6	48.4	57.5	100	1953/09/02	15	1955/11/29	60.7	2007	53.2	1976

												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	3.13	8.86	1978	0.45	1955	2.32	23/1998	11	6	2	1	5.6	23.4	1978
February	2.75	6.44	1979	0.55	2002	1.95	13/1966	9	6	2	1	7.2	51.5	2010
March	3.82	7.33	2010	0.68	1966	2.57	13/2010	11	7	3	1	3.3	13.4	1958
April	3.47	9.05	2007	0.52	1985	4.19	15/2007	11	7	2	1	0.3	4.3	1971
May	3.55	7.40	1948	0.47	1964	2.49	02/1989	11	7	2	1	-	-	-
June	3.62	8.08	2003	0.11	1949	4.62	29/1973	10	6	2	1	-	-	-
July	4.11	10.42	1994	0.64	1957	4.68	12/2004	9	6	2	1	-	-	-
August	3.85	10.29	2009	0.49	1964	4.77	27/1971	9	6	2	1	-	-	-
September	3.57	13.07	1999	0.21	2005	6.63	16/1999	8	5	2	1	-	-	-
October	2.93	8.68	2005	0.09	1963	5.53	08/2005	8	5	2	1	0.0	2.1	1979
November	3.20	9.06	1972	0.32	1976	3.99	07/1977	10	6	2	1	0.6	8.8	1953
December	3.49	8.86	2009	0.25	1955	2.72	11/2008	11	6	3	1	3.4	24.1	2009

Annual	41.49	56.45	1996	29.34	1965	6.63	1999/09/16	118	72	28	11	20.5	57.0	1978

Winter	9.37	20.79	1979	4.21	1981	2.72	2008/12/11	31	18	7	2	16.3	78.7	2010
Spring	10.84	22.10	1983	6.13	1963	4.19	2007/04/15	33	20	8	3	3.7	13.4	1958
Summer	11.58	18.43	2009	4.39	1966	4.77	1971/08/27	28	18	7	3	-	-	-
Fall	9.70	18.93	1999	3.97	2001	6.63	1999/09/16	26	16	7	2	0.6	8.8	1953

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