S
M
T
W
T
F
S
26
68°
43°
27
57°
47°
28
56°
46°
29
66°
47°
30
75°
48°
1
72°
52°
2
74°
49°
3
81°
56°
4
77°
53°
5
63°
52°
6
57°
51°
7
64°
50°
8
62°
49°
9
69°
48°
10
66°
48°
11
72°
51°
12
79°
51°
13
60°
50°
14
62°
48°
15
56°
46°
16
56°
45°
17
62°
49°
18
63°
51°
19
67°
50°
20
69°
53°
21
76°
53°
22
71°
52°
23
69°
51°
24
68°
52°
25
67°
51°
26
61°
50°
27
62°
50°
28
63°
47°
29
67°
51°
30
67°
51°
31
64°
52°
1
64°
55°
2
67°
52°
3
69°
52°
4
72°
53°
5
72°
53°
6
71°
56°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
May Weather in Seattle
Seattle's May 2026 forecast shows daily high temperatures ranging from 56° to 79°, with overnight lows between 45° and 56°. The average high for May is 66° with an average low of 51°. AccuWeather's monthly forecast extends further ahead than any other source, with day-by-day RealFeel® Temperatures giving a complete picture of how May weather will actually feel in Seattle. See also: June | July | August.