Template:Seattle weatherbox
| Month | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Year |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Record high °F (°C) | 67 (19) |
70 (21) |
79 (26) |
89 (32) |
93 (34) |
108 (42) |
103 (39) |
99 (37) |
98 (37) |
89 (32) |
74 (23) |
66 (19) |
108 (42) |
| Mean maximum °F (°C) | 57.0 (13.9) |
59.1 (15.1) |
66.4 (19.1) |
74.3 (23.5) |
81.9 (27.7) |
85.8 (29.9) |
91.2 (32.9) |
89.9 (32.2) |
84.1 (28.9) |
72.0 (22.2) |
61.6 (16.4) |
56.8 (13.8) |
94.1 (34.5) |
| Mean daily maximum °F (°C) | 48.0 (8.9) |
50.3 (10.2) |
54.2 (12.3) |
59.3 (15.2) |
66.3 (19.1) |
71.1 (21.7) |
77.4 (25.2) |
77.6 (25.3) |
71.6 (22.0) |
60.5 (15.8) |
52.1 (11.2) |
47.0 (8.3) |
61.3 (16.3) |
| Daily mean °F (°C) | 42.8 (6.0) |
44.0 (6.7) |
47.1 (8.4) |
51.3 (10.7) |
57.5 (14.2) |
62.0 (16.7) |
67.1 (19.5) |
67.4 (19.7) |
62.6 (17.0) |
53.8 (12.1) |
46.5 (8.1) |
42.0 (5.6) |
53.7 (12.1) |
| Mean daily minimum °F (°C) | 37.7 (3.2) |
37.7 (3.2) |
39.9 (4.4) |
43.3 (6.3) |
48.7 (9.3) |
53.0 (11.7) |
56.8 (13.8) |
57.2 (14.0) |
53.6 (12.0) |
47.0 (8.3) |
40.9 (4.9) |
37.1 (2.8) |
46.1 (7.8) |
| Mean minimum °F (°C) | 26.1 (−3.3) |
27.3 (−2.6) |
31.3 (−0.4) |
35.6 (2.0) |
40.6 (4.8) |
46.6 (8.1) |
51.5 (10.8) |
51.7 (10.9) |
45.8 (7.7) |
36.8 (2.7) |
29.2 (−1.6) |
25.4 (−3.7) |
21.5 (−5.8) |
| Record low °F (°C) | 0 (−18) |
1 (−17) |
11 (−12) |
29 (−2) |
28 (−2) |
38 (3) |
43 (6) |
44 (7) |
35 (2) |
28 (−2) |
6 (−14) |
6 (−14) |
0 (−18) |
| Average precipitation inches (mm) | 5.78 (147) |
3.76 (96) |
4.17 (106) |
3.18 (81) |
1.88 (48) |
1.45 (37) |
0.60 (15) |
0.97 (25) |
1.61 (41) |
3.91 (99) |
6.31 (160) |
5.72 (145) |
39.34 (999) |
| Average snowfall inches (cm) | 1.8 (4.6) |
2.2 (5.6) |
0.4 (1.0) |
0.0 (0.0) |
0.0 (0.0) |
0.0 (0.0) |
0.0 (0.0) |
0.0 (0.0) |
0.0 (0.0) |
0.0 (0.0) |
0.2 (0.51) |
1.7 (4.3) |
6.3 (16) |
| Average precipitation days (≥ 0.01 in) | 18.7 | 15.9 | 17.1 | 15.0 | 11.3 | 9.2 | 4.7 | 4.9 | 8.3 | 14.3 | 18.4 | 18.4 | 156.2 |
| Average snowy days (≥ 0.1 in) | 1.4 | 1.2 | 0.4 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.2 | 1.5 | 4.7 |
| Average relative humidity (%) | 78.0 | 75.2 | 73.6 | 71.4 | 68.9 | 67.1 | 65.4 | 68.2 | 73.2 | 78.6 | 79.8 | 80.1 | 73.3 |
| Average dew point °F (°C) | 33.1 (0.6) |
35.1 (1.7) |
36.3 (2.4) |
38.8 (3.8) |
43.5 (6.4) |
48.2 (9.0) |
51.4 (10.8) |
52.7 (11.5) |
50.2 (10.1) |
45.1 (7.3) |
38.8 (3.8) |
34.3 (1.3) |
42.3 (5.7) |
| Mean monthly sunshine hours | 69.8 | 108.8 | 178.4 | 207.3 | 253.7 | 268.4 | 312.0 | 281.4 | 221.7 | 142.6 | 72.7 | 52.9 | 2,169.7 |
| Percent possible sunshine | 25 | 38 | 48 | 51 | 54 | 56 | 65 | 64 | 59 | 42 | 26 | 20 | 49 |
| Average ultraviolet index | 1 | 2 | 3 | 5 | 6 | 7 | 7 | 6 | 5 | 3 | 1 | 1 | 4 |
| Source 1: NOAA (relative humidity, dew point and sun 1961–1990)[2][3][4] | |||||||||||||
| Source 2: Weather Atlas (UV)[5] | |||||||||||||
Notes
References
- ^ "National Weather Service - NWS Seattle". NWS Seattle, WA. Retrieved October 25, 2015.
- ^ "NowData – NOAA Online Weather Data". National Oceanic and Atmospheric Administration. Retrieved June 27, 2021.
- ^ "Summary of Monthly Normals 1991–2020". National Oceanic and Atmospheric Administration. Retrieved May 20, 2021.
- ^ "WMO Climate Normals for Seattle/Seattle–Tacoma INTL A, WA 1961–1990". National Oceanic and Atmospheric Administration. Archived from the original on 2023-06-27. Retrieved July 18, 2020.
- ^ "Seattle, WA - Detailed climate information and monthly weather forecast". Weather Atlas. Yu Media Group. Retrieved January 1, 2020.