S
M
T
W
T
F
S
30
87°
59°
31
78°
61°
1
78°
63°
2
81°
66°
3
86°
68°
4
86°
67°
5
87°
60°
6
83°
57°
7
78°
56°
8
77°
57°
9
79°
64°
10
79°
61°
11
76°
55°
12
74°
54°
13
75°
59°
14
77°
61°
15
76°
52°
16
81°
52°
17
72°
53°
18
72°
52°
19
71°
52°
20
71°
51°
21
72°
51°
22
72°
52°
23
73°
51°
24
75°
56°
25
77°
58°
26
78°
55°
27
79°
52°
28
70°
58°
29
73°
52°
30
77°
51°
1
70°
54°
2
71°
51°
3
67°
52°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Decatur
Decatur's September 2026 forecast shows daily high temperatures ranging from 67° to 87°, with overnight lows between 51° and 68°. The average high for September is 77° with an average low of 56°. AccuWeather's monthly forecast extends further ahead than any other source, with day-by-day RealFeel® Temperatures giving a complete picture of how September weather will actually feel in Decatur. See also: October | November | December.
