S
M
T
W
T
F
S
26
57°
35°
27
57°
35°
28
60°
44°
29
60°
41°
30
63°
40°
1
67°
46°
2
69°
49°
3
72°
49°
4
72°
50°
5
74°
49°
6
65°
46°
7
71°
49°
8
73°
51°
9
75°
52°
10
73°
52°
11
74°
51°
12
76°
48°
13
65°
42°
14
66°
48°
15
67°
46°
16
67°
46°
17
68°
45°
18
71°
48°
19
72°
49°
20
73°
50°
21
72°
45°
22
69°
45°
23
69°
46°
24
70°
46°
25
72°
47°
26
71°
47°
27
76°
52°
28
76°
56°
29
71°
58°
30
75°
58°
31
76°
52°
1
75°
49°
2
72°
49°
3
74°
56°
4
79°
59°
5
82°
61°
6
84°
55°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
May Weather in Decorah
Decorah's May 2026 forecast shows daily high temperatures ranging from 57° to 84°, with overnight lows between 35° and 61°. The average high for May is 71° with an average low of 49°. 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 Decorah. See also: June | July | August.
