S
M
T
W
T
F
S
30
95°
66°
31
94°
69°
1
94°
68°
2
93°
67°
3
93°
68°
4
92°
65°
5
92°
65°
6
93°
66°
7
91°
67°
8
90°
66°
9
89°
67°
10
92°
66°
11
92°
66°
12
90°
65°
13
86°
65°
14
86°
64°
15
87°
65°
16
86°
64°
17
86°
64°
18
87°
63°
19
86°
59°
20
85°
57°
21
83°
58°
22
85°
60°
23
87°
62°
24
86°
61°
25
85°
62°
26
88°
61°
27
88°
61°
28
84°
60°
29
86°
59°
30
87°
60°
1
87°
59°
2
Hist. Avg.
85°
60°
3
Hist. Avg.
84°
60°
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 83° to 95°, with overnight lows between 57° and 69°. The average high for September is 89° 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.
