S
M
T
W
T
F
S
30
88°
64°
31
89°
65°
1
88°
66°
2
87°
67°
3
88°
64°
4
83°
63°
5
83°
63°
6
87°
67°
7
87°
65°
8
86°
65°
9
86°
66°
10
85°
66°
11
86°
65°
12
86°
67°
13
85°
66°
14
85°
65°
15
84°
61°
16
84°
62°
17
85°
63°
18
84°
60°
19
84°
63°
20
83°
64°
21
82°
63°
22
83°
62°
23
83°
61°
24
81°
62°
25
81°
58°
26
79°
61°
27
79°
57°
28
Hist. Avg.
79°
59°
29
Hist. Avg.
79°
58°
30
Hist. Avg.
79°
58°
1
Hist. Avg.
78°
57°
2
Hist. Avg.
78°
57°
3
Hist. Avg.
78°
56°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
*Temporarily Unavailable
September Weather in Decatur
Decatur's September 2026 forecast shows daily high temperatures ranging from 79° to 89°, with overnight lows between 57° and 67°. The average high for September is 85° with an average low of 63°. 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.
