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
65°
50°
8
63°
50°
9
69°
52°
10
69°
53°
11
71°
52°
12
69°
53°
13
74°
51°
14
73°
50°
15
68°
49°
16
66°
50°
17
68°
51°
18
66°
52°
19
68°
51°
20
67°
50°
21
62°
51°
22
62°
48°
23
65°
48°
24
70°
54°
25
70°
52°
26
62°
47°
27
62°
47°
28
67°
55°
29
64°
56°
30
65°
53°
31
72°
54°
1
73°
56°
2
73°
55°
3
66°
50°
4
71°
52°
5
72°
50°
6
64°
51°
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 62° to 74°, with overnight lows between 47° and 56°. The average high for May is 68° 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.