Month | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Year |
---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Record high °F (°C) | 74 (23) |
79 (26) |
87 (31) |
95 (35) |
97 (36) |
102 (39) |
104 (40) |
106 (41) |
102 (39) |
96 (36) |
84 (29) |
73 (23) |
106 (41) |
Mean maximum °F (°C) | 63.3 (17.4) |
63.5 (17.5) |
73.8 (23.2) |
84.3 (29.1) |
90.2 (32.3) |
94.8 (34.9) |
97.1 (36.2) |
94.8 (34.9) |
90.6 (32.6) |
82.6 (28.1) |
72.4 (22.4) |
64.2 (17.9) |
98.1 (36.7) |
Mean daily maximum °F (°C) | 41.3 (5.2) |
44.3 (6.8) |
52.8 (11.6) |
64.7 (18.2) |
74.4 (23.6) |
83.2 (28.4) |
87.8 (31.0) |
85.8 (29.9) |
78.9 (26.1) |
67.2 (19.6) |
55.9 (13.3) |
46.0 (7.8) |
65.2 (18.4) |
Daily mean °F (°C) | 33.7 (0.9) |
35.9 (2.2) |
43.6 (6.4) |
54.5 (12.5) |
64.3 (17.9) |
73.5 (23.1) |
78.7 (25.9) |
76.8 (24.9) |
69.9 (21.1) |
58.2 (14.6) |
47.4 (8.6) |
38.6 (3.7) |
56.3 (13.5) |
Mean daily minimum °F (°C) | 26.0 (−3.3) |
27.5 (−2.5) |
34.3 (1.3) |
44.3 (6.8) |
54.2 (12.3) |
63.9 (17.7) |
69.6 (20.9) |
67.9 (19.9) |
60.9 (16.1) |
49.2 (9.6) |
38.8 (3.8) |
31.2 (−0.4) |
47.3 (8.5) |
Mean minimum °F (°C) | 10.7 (−11.8) |
13.7 (−10.2) |
20.8 (−6.2) |
33.0 (0.6) |
43.1 (6.2) |
53.2 (11.8) |
62.2 (16.8) |
60.3 (15.7) |
49.5 (9.7) |
37.1 (2.8) |
26.4 (−3.1) |
19.0 (−7.2) |
8.6 (−13.0) |
Record low °F (°C) | −7 (−22) |
−11 (−24) |
5 (−15) |
14 (−10) |
28 (−2) |
44 (7) |
51 (11) |
44 (7) |
35 (2) |
25 (−4) |
8 (−13) |
−5 (−21) |
−11 (−24) |
Average precipitation inches (mm) | 3.13 (80) |
2.75 (70) |
3.96 (101) |
3.47 (88) |
3.34 (85) |
4.04 (103) |
4.38 (111) |
4.29 (109) |
4.40 (112) |
3.47 (88) |
2.91 (74) |
3.97 (101) |
44.11 (1,120) |
Average snowfall inches (cm) | 7.1 (18) |
8.4 (21) |
3.6 (9.1) |
0.3 (0.76) |
0.0 (0.0) |
0.0 (0.0) |
0.0 (0.0) |
0.0 (0.0) |
0.0 (0.0) |
0.0 (0.0) |
0.2 (0.51) |
3.5 (8.9) |
23.1 (59) |
Average precipitation days (≥ 0.01 in) | 11.0 | 9.7 | 10.9 | 10.9 | 11.0 | 10.3 | 10.1 | 8.9 | 9.3 | 9.1 | 8.6 | 11.0 | 120.8 |
Average snowy days (≥ 0.1 in) | 4.1 | 3.8 | 2.0 | 0.2 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.1 | 1.8 | 12.0 |
Average relative humidity (%) | 66.2 | 63.6 | 61.7 | 60.4 | 65.4 | 67.8 | 69.6 | 70.4 | 71.6 | 70.8 | 68.4 | 67.7 | 67.0 |
Average dew point °F (°C) | 19.8 (−6.8) |
21.0 (−6.1) |
28.6 (−1.9) |
37.0 (2.8) |
49.5 (9.7) |
59.2 (15.1) |
64.6 (18.1) |
63.7 (17.6) |
57.2 (14.0) |
45.7 (7.6) |
35.6 (2.0) |
25.5 (−3.6) |
42.3 (5.7) |
Mean monthly sunshine hours | 155.7 | 154.7 | 202.8 | 217.0 | 245.1 | 271.2 | 275.6 | 260.1 | 219.3 | 204.5 | 154.7 | 137.7 | 2,498.4 |
Percent possible sunshine | 52 | 52 | 55 | 55 | 55 | 61 | 61 | 61 | 59 | 59 | 52 | 47 | 56 |
Average ultraviolet index | 2 | 3 | 4 | 6 | 8 | 9 | 9 | 8 | 6 | 4 | 2 | 2 | 5 |
Source 1: NOAA (relative humidity, dew point and sun 1961–1990) [4] [5] [2] | |||||||||||||
Source 2: Weather Atlas (UV index) [6] |
Climate data for Philadelphia | |||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Month | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Year |
Average sea temperature °F (°C) | 41.8 (5.5) |
39.9 (4.4) |
41.2 (5.1) |
46.7 (8.2) |
53.9 (12.2) |
66.3 (19.0) |
74.0 (23.3) |
75.9 (24.4) |
71.4 (21.9) |
64.2 (17.9) |
55.1 (12.8) |
47.7 (8.8) |
56.5 (13.6) |
Mean daily daylight hours | 10.0 | 11.0 | 12.0 | 13.0 | 14.0 | 15.0 | 15.0 | 14.0 | 12.0 | 11.0 | 10.0 | 9.0 | 12.2 |
Source: Weather Atlas [6] |
Month | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Year |
---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Record high °F (°C) | 74 (23) |
79 (26) |
87 (31) |
95 (35) |
97 (36) |
102 (39) |
104 (40) |
106 (41) |
102 (39) |
96 (36) |
84 (29) |
73 (23) |
106 (41) |
Mean maximum °F (°C) | 63.3 (17.4) |
63.5 (17.5) |
73.8 (23.2) |
84.3 (29.1) |
90.2 (32.3) |
94.8 (34.9) |
97.1 (36.2) |
94.8 (34.9) |
90.6 (32.6) |
82.6 (28.1) |
72.4 (22.4) |
64.2 (17.9) |
98.1 (36.7) |
Mean daily maximum °F (°C) | 41.3 (5.2) |
44.3 (6.8) |
52.8 (11.6) |
64.7 (18.2) |
74.4 (23.6) |
83.2 (28.4) |
87.8 (31.0) |
85.8 (29.9) |
78.9 (26.1) |
67.2 (19.6) |
55.9 (13.3) |
46.0 (7.8) |
65.2 (18.4) |
Daily mean °F (°C) | 33.7 (0.9) |
35.9 (2.2) |
43.6 (6.4) |
54.5 (12.5) |
64.3 (17.9) |
73.5 (23.1) |
78.7 (25.9) |
76.8 (24.9) |
69.9 (21.1) |
58.2 (14.6) |
47.4 (8.6) |
38.6 (3.7) |
56.3 (13.5) |
Mean daily minimum °F (°C) | 26.0 (−3.3) |
27.5 (−2.5) |
34.3 (1.3) |
44.3 (6.8) |
54.2 (12.3) |
63.9 (17.7) |
69.6 (20.9) |
67.9 (19.9) |
60.9 (16.1) |
49.2 (9.6) |
38.8 (3.8) |
31.2 (−0.4) |
47.3 (8.5) |
Mean minimum °F (°C) | 10.7 (−11.8) |
13.7 (−10.2) |
20.8 (−6.2) |
33.0 (0.6) |
43.1 (6.2) |
53.2 (11.8) |
62.2 (16.8) |
60.3 (15.7) |
49.5 (9.7) |
37.1 (2.8) |
26.4 (−3.1) |
19.0 (−7.2) |
8.6 (−13.0) |
Record low °F (°C) | −7 (−22) |
−11 (−24) |
5 (−15) |
14 (−10) |
28 (−2) |
44 (7) |
51 (11) |
44 (7) |
35 (2) |
25 (−4) |
8 (−13) |
−5 (−21) |
−11 (−24) |
Average precipitation inches (mm) | 3.13 (80) |
2.75 (70) |
3.96 (101) |
3.47 (88) |
3.34 (85) |
4.04 (103) |
4.38 (111) |
4.29 (109) |
4.40 (112) |
3.47 (88) |
2.91 (74) |
3.97 (101) |
44.11 (1,120) |
Average snowfall inches (cm) | 7.1 (18) |
8.4 (21) |
3.6 (9.1) |
0.3 (0.76) |
0.0 (0.0) |
0.0 (0.0) |
0.0 (0.0) |
0.0 (0.0) |
0.0 (0.0) |
0.0 (0.0) |
0.2 (0.51) |
3.5 (8.9) |
23.1 (59) |
Average precipitation days (≥ 0.01 in) | 11.0 | 9.7 | 10.9 | 10.9 | 11.0 | 10.3 | 10.1 | 8.9 | 9.3 | 9.1 | 8.6 | 11.0 | 120.8 |
Average snowy days (≥ 0.1 in) | 4.1 | 3.8 | 2.0 | 0.2 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.1 | 1.8 | 12.0 |
Average relative humidity (%) | 66.2 | 63.6 | 61.7 | 60.4 | 65.4 | 67.8 | 69.6 | 70.4 | 71.6 | 70.8 | 68.4 | 67.7 | 67.0 |
Average dew point °F (°C) | 19.8 (−6.8) |
21.0 (−6.1) |
28.6 (−1.9) |
37.0 (2.8) |
49.5 (9.7) |
59.2 (15.1) |
64.6 (18.1) |
63.7 (17.6) |
57.2 (14.0) |
45.7 (7.6) |
35.6 (2.0) |
25.5 (−3.6) |
42.3 (5.7) |
Mean monthly sunshine hours | 155.7 | 154.7 | 202.8 | 217.0 | 245.1 | 271.2 | 275.6 | 260.1 | 219.3 | 204.5 | 154.7 | 137.7 | 2,498.4 |
Percent possible sunshine | 52 | 52 | 55 | 55 | 55 | 61 | 61 | 61 | 59 | 59 | 52 | 47 | 56 |
Average ultraviolet index | 2 | 3 | 4 | 6 | 8 | 9 | 9 | 8 | 6 | 4 | 2 | 2 | 5 |
Source 1: NOAA (relative humidity, dew point and sun 1961–1990) [4] [5] [2] | |||||||||||||
Source 2: Weather Atlas (UV index) [6] |
Climate data for Philadelphia | |||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Month | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Year |
Average sea temperature °F (°C) | 41.8 (5.5) |
39.9 (4.4) |
41.2 (5.1) |
46.7 (8.2) |
53.9 (12.2) |
66.3 (19.0) |
74.0 (23.3) |
75.9 (24.4) |
71.4 (21.9) |
64.2 (17.9) |
55.1 (12.8) |
47.7 (8.8) |
56.5 (13.6) |
Mean daily daylight hours | 10.0 | 11.0 | 12.0 | 13.0 | 14.0 | 15.0 | 15.0 | 14.0 | 12.0 | 11.0 | 10.0 | 9.0 | 12.2 |
Source: Weather Atlas [6] |