S
M
T
W
T
F
S
30
92°
71°
31
94°
70°
1
95°
69°
2
97°
71°
3
98°
72°
4
97°
72°
5
99°
70°
6
98°
71°
7
93°
72°
8
92°
71°
9
93°
71°
10
94°
72°
11
90°
72°
12
89°
73°
13
93°
72°
14
88°
69°
15
90°
66°
16
90°
70°
17
89°
69°
18
88°
67°
19
84°
60°
20
79°
66°
21
88°
66°
22
86°
65°
23
86°
66°
24
85°
66°
25
86°
65°
26
86°
65°
27
85°
64°
28
85°
65°
29
84°
65°
30
85°
64°
1
85°
62°
2
81°
57°
3
73°
53°
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 73° to 98°, with overnight lows between 53° and 73°. The average high for September is 87° with an average low of 67°. 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.
