S
M
T
W
T
F
S
30
82°
51°
31
74°
53°
1
74°
58°
2
75°
54°
3
80°
60°
4
82°
56°
5
81°
48°
6
73°
49°
7
73°
47°
8
72°
49°
9
75°
56°
10
74°
50°
11
71°
46°
12
70°
45°
13
72°
47°
14
71°
50°
15
70°
44°
16
69°
44°
17
68°
43°
18
67°
43°
19
67°
44°
20
68°
43°
21
67°
43°
22
67°
44°
23
70°
48°
24
72°
50°
25
73°
51°
26
73°
45°
27
72°
41°
28
65°
49°
29
65°
48°
30
72°
44°
1
69°
46°
2
68°
47°
3
63°
40°
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 63° to 82°, with overnight lows between 40° and 60°. The average high for September is 72° with an average low of 48°. 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.
