S
M
T
W
T
F
S
30
91°
70°
31
93°
70°
1
96°
70°
2
98°
72°
3
95°
74°
4
95°
73°
5
96°
74°
6
92°
71°
7
84°
68°
8
86°
69°
9
89°
70°
10
94°
69°
11
94°
68°
12
88°
69°
13
88°
68°
14
86°
68°
15
89°
67°
16
84°
62°
17
79°
64°
18
77°
66°
19
77°
66°
20
79°
65°
21
82°
65°
22
79°
64°
23
83°
64°
24
81°
63°
25
77°
64°
26
80°
64°
27
80°
58°
28
75°
54°
29
73°
53°
30
73°
53°
1
74°
55°
2
72°
60°
3
73°
58°
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 72° to 96°, with overnight lows between 53° and 74°. The average high for September is 83° 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 September weather will actually feel in Decatur. See also: October | November | December.
