S
M
T
W
T
F
S
30
84°
67°
31
89°
71°
1
92°
74°
2
94°
73°
3
94°
74°
4
90°
71°
5
82°
68°
6
77°
61°
7
79°
59°
8
86°
59°
9
86°
69°
10
82°
64°
11
80°
65°
12
82°
65°
13
81°
52°
14
72°
59°
15
87°
65°
16
84°
63°
17
77°
57°
18
74°
53°
19
71°
50°
20
70°
52°
21
71°
52°
22
75°
55°
23
77°
55°
24
74°
50°
25
71°
55°
26
77°
55°
27
77°
56°
28
76°
55°
29
76°
55°
30
75°
54°
1
75°
51°
2
68°
53°
3
74°
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 68° to 87°, with overnight lows between 50° and 65°. The average high for September is 76° with an average low of 56°. 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.
