S
M
T
W
T
F
S
30
94°
71°
31
96°
71°
1
99°
72°
2
97°
72°
3
95°
72°
4
92°
72°
5
90°
72°
6
95°
71°
7
93°
68°
8
92°
70°
9
91°
70°
10
90°
69°
11
91°
69°
12
90°
68°
13
91°
67°
14
89°
66°
15
88°
63°
16
83°
66°
17
84°
65°
18
83°
66°
19
85°
65°
20
85°
65°
21
88°
64°
22
89°
65°
23
89°
64°
24
88°
65°
25
85°
64°
26
81°
63°
27
83°
58°
28
80°
54°
29
79°
53°
30
80°
53°
1
79°
54°
2
82°
54°
3
77°
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 77° to 97°, with overnight lows between 53° and 72°. The average high for September is 87° with an average low of 64°. 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.
