S
M
T
W
T
F
S
26
73°
51°
27
68°
49°
28
62°
46°
29
57°
40°
30
57°
35°
1
55°
34°
2
62°
47°
3
67°
47°
4
72°
40°
5
57°
36°
6
51°
34°
7
53°
37°
8
63°
42°
9
62°
44°
10
65°
44°
11
63°
45°
12
65°
45°
13
67°
46°
14
61°
39°
15
65°
46°
16
66°
47°
17
66°
54°
18
68°
54°
19
73°
55°
20
75°
57°
21
74°
54°
22
66°
50°
23
68°
47°
24
66°
48°
25
66°
51°
26
67°
55°
27
70°
54°
28
69°
51°
29
69°
52°
30
75°
54°
31
71°
52°
1
70°
57°
2
77°
54°
3
71°
52°
4
73°
52°
5
73°
53°
6
74°
53°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
May Weather in Onalaska
Onalaska's May 2026 forecast shows daily high temperatures ranging from 51° to 77°, with overnight lows between 34° and 57°. The average high for May is 67° with an average low of 48°. 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 Onalaska. See also: June | July | August.
