S
M
T
W
T
F
S
26
85°
59°
27
86°
61°
28
75°
65°
29
81°
62°
30
69°
55°
1
69°
48°
2
70°
48°
3
70°
42°
4
82°
46°
5
79°
56°
6
74°
57°
7
72°
52°
8
73°
48°
9
78°
54°
10
83°
56°
11
78°
54°
12
80°
52°
13
84°
57°
14
76°
49°
15
84°
61°
16
86°
63°
17
91°
68°
18
92°
72°
19
90°
71°
20
78°
65°
21
80°
61°
22
82°
63°
23
82°
66°
24
83°
65°
25
84°
65°
26
83°
67°
27
85°
67°
28
83°
62°
29
81°
66°
30
79°
64°
31
79°
61°
1
80°
63°
2
80°
64°
3
82°
65°
4
85°
67°
5
87°
68°
6
87°
68°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
May Weather in Decatur
Decatur's May 2026 forecast shows daily high temperatures ranging from 78° to 92°, with overnight lows between 61° and 72°. The average high for May is 84° with an average low of 65°. 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 Decatur. See also: June | July | August.
