S
M
T
W
T
F
S
26
71°
33°
27
57°
46°
28
56°
45°
29
70°
39°
30
79°
42°
1
74°
45°
2
77°
50°
3
86°
48°
4
77°
48°
5
65°
53°
6
62°
51°
7
69°
46°
8
63°
46°
9
72°
47°
10
66°
49°
11
75°
52°
12
83°
48°
13
61°
47°
14
61°
43°
15
55°
42°
16
56°
42°
17
64°
43°
18
68°
47°
19
71°
45°
20
72°
47°
21
77°
48°
22
72°
47°
23
68°
46°
24
68°
46°
25
71°
49°
26
70°
48°
27
70°
49°
28
64°
46°
29
65°
44°
30
67°
45°
31
73°
49°
1
73°
51°
2
68°
51°
3
66°
45°
4
65°
45°
5
64°
46°
6
65°
45°
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 55° to 77°, with overnight lows between 42° and 51°. The average high for May is 67° with an average low of 46°. 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.
