S
M
T
W
T
F
S
26
60°
43°
27
73°
42°
28
69°
51°
29
54°
45°
30
54°
40°
1
45°
36°
2
42°
33°
3
59°
31°
4
73°
48°
5
68°
47°
6
57°
38°
7
55°
44°
8
59°
49°
9
69°
51°
10
55°
41°
11
54°
38°
12
56°
47°
13
61°
44°
14
62°
48°
15
69°
49°
16
64°
49°
17
65°
50°
18
67°
49°
19
70°
50°
20
66°
45°
21
65°
46°
22
66°
47°
23
67°
50°
24
68°
50°
25
68°
51°
26
69°
50°
27
70°
48°
28
72°
52°
29
75°
55°
30
77°
57°
31
78°
58°
1
77°
57°
2
75°
55°
3
79°
59°
4
81°
60°
5
81°
61°
6
80°
60°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
May Weather in Dekalb
Dekalb's May 2026 forecast shows daily high temperatures ranging from 54° to 81°, with overnight lows between 38° and 61°. The average high for May is 68° with an average low of 50°. 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 Dekalb. See also: June | July | August.
