S
M
T
W
T
F
S
26
68°
40°
27
60°
49°
28
59°
48°
29
66°
48°
30
74°
47°
1
71°
50°
2
74°
52°
3
80°
52°
4
81°
53°
5
66°
55°
6
59°
53°
7
64°
50°
8
64°
50°
9
68°
49°
10
67°
50°
11
71°
54°
12
83°
53°
13
60°
53°
14
63°
51°
15
53°
47°
16
58°
46°
17
63°
43°
18
67°
47°
19
64°
54°
20
68°
53°
21
76°
49°
22
78°
52°
23
67°
53°
24
71°
53°
25
64°
49°
26
63°
49°
27
73°
54°
28
77°
52°
29
64°
46°
30
64°
47°
31
67°
48°
1
72°
52°
2
73°
52°
3
72°
53°
4
73°
52°
5
74°
50°
6
68°
50°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
May Weather in Issaquah
Issaquah's May 2026 forecast shows daily high temperatures ranging from 63° to 77°, with overnight lows between 46° and 54°. The average high for May is 70° 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 Issaquah. See also: June | July | August.
