S
M
T
W
T
F
S
30
92°
71°
31
94°
70°
1
95°
69°
2
97°
71°
3
99°
73°
4
98°
73°
5
98°
74°
6
97°
73°
7
93°
72°
8
90°
74°
9
93°
70°
10
94°
72°
11
93°
69°
12
91°
69°
13
93°
70°
14
89°
69°
15
87°
69°
16
84°
63°
17
82°
66°
18
78°
67°
19
78°
67°
20
79°
66°
21
80°
66°
22
84°
65°
23
83°
65°
24
81°
64°
25
80°
65°
26
81°
62°
27
78°
56°
28
74°
54°
29
73°
53°
30
75°
53°
1
74°
55°
2
75°
60°
3
73°
61°
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 99°, with overnight lows between 53° and 74°. The average high for September is 85° with an average low of 66°. 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.
