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
56°
41°
7
56°
39°
8
60°
50°
9
67°
48°
10
61°
41°
11
56°
38°
12
58°
49°
13
56°
42°
14
59°
43°
15
66°
51°
16
70°
50°
17
72°
51°
18
76°
53°
19
76°
54°
20
75°
57°
21
78°
50°
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 56° to 81°, with overnight lows between 38° and 61°. The average high for May is 70° with an average low of 52°. 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.
