Month | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Year |
---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Record high °F (°C) | 79 (26) |
81 (27) |
87 (31) |
94 (34) |
97 (36) |
103 (39) |
99 (37) |
98 (37) |
106 (41) |
102 (39) |
86 (30) |
76 (24) |
106 (41) |
Mean maximum °F (°C) | 67.1 (19.5) |
71.8 (22.1) |
76.4 (24.7) |
80.7 (27.1) |
81.4 (27.4) |
84.6 (29.2) |
80.5 (26.9) |
83.4 (28.6) |
90.8 (32.7) |
87.9 (31.1) |
75.8 (24.3) |
66.4 (19.1) |
94.0 (34.4) |
Mean daily maximum °F (°C) | 57.8 (14.3) |
60.4 (15.8) |
62.1 (16.7) |
63.0 (17.2) |
64.1 (17.8) |
66.5 (19.2) |
66.3 (19.1) |
67.9 (19.9) |
70.2 (21.2) |
69.8 (21.0) |
63.7 (17.6) |
57.9 (14.4) |
64.1 (17.8) |
Daily mean °F (°C) | 52.2 (11.2) |
54.2 (12.3) |
55.5 (13.1) |
56.4 (13.6) |
57.8 (14.3) |
59.7 (15.4) |
60.3 (15.7) |
61.7 (16.5) |
62.9 (17.2) |
62.1 (16.7) |
57.2 (14.0) |
52.5 (11.4) |
57.7 (14.3) |
Mean daily minimum °F (°C) | 46.6 (8.1) |
47.9 (8.8) |
48.9 (9.4) |
49.7 (9.8) |
51.4 (10.8) |
53.0 (11.7) |
54.4 (12.4) |
55.5 (13.1) |
55.6 (13.1) |
54.4 (12.4) |
50.7 (10.4) |
47.0 (8.3) |
51.3 (10.7) |
Mean minimum °F (°C) | 40.5 (4.7) |
42.0 (5.6) |
43.7 (6.5) |
45.0 (7.2) |
48.0 (8.9) |
50.1 (10.1) |
51.6 (10.9) |
52.9 (11.6) |
52.0 (11.1) |
49.9 (9.9) |
44.9 (7.2) |
40.7 (4.8) |
38.8 (3.8) |
Record low °F (°C) | 29 (−2) |
31 (−1) |
33 (1) |
40 (4) |
42 (6) |
46 (8) |
47 (8) |
46 (8) |
47 (8) |
43 (6) |
38 (3) |
27 (−3) |
27 (−3) |
Average precipitation inches (mm) | 4.40 (112) |
4.37 (111) |
3.15 (80) |
1.60 (41) |
0.70 (18) |
0.20 (5.1) |
0.01 (0.25) |
0.06 (1.5) |
0.10 (2.5) |
0.94 (24) |
2.60 (66) |
4.76 (121) |
22.89 (581) |
Average precipitation days (≥ 0.01 in) | 11.2 | 10.8 | 10.8 | 6.8 | 4.0 | 1.6 | 0.7 | 1.1 | 1.2 | 3.5 | 7.9 | 11.6 | 71.2 |
Average relative humidity (%) | 80 | 77 | 75 | 72 | 72 | 71 | 75 | 75 | 73 | 71 | 75 | 78 | 75 |
Mean monthly sunshine hours | 185.9 | 207.7 | 269.1 | 309.3 | 325.1 | 311.4 | 313.3 | 287.4 | 271.4 | 247.1 | 173.4 | 160.6 | 3,061.7 |
Percent possible sunshine | 61 | 69 | 73 | 78 | 74 | 70 | 70 | 68 | 73 | 71 | 57 | 54 | 69 |
Average ultraviolet index | 2 | 3 | 5 | 7 | 9 | 10 | 10 | 9 | 7 | 5 | 3 | 2 | 6 |
Source 1: NOAA (sun 1961–1974) [1] [2] [3] [4] | |||||||||||||
Source 2: Met Office (humidity) [5], Weather Atlas (UV) [6] |