S
M
T
W
T
F
S
30
82°
61°
31
81°
66°
1
88°
70°
2
90°
70°
3
84°
66°
4
79°
66°
5
79°
57°
6
75°
54°
7
77°
55°
8
81°
50°
9
84°
61°
10
79°
66°
11
79°
57°
12
82°
57°
13
82°
66°
14
68°
50°
15
77°
46°
16
84°
57°
17
81°
68°
18
75°
57°
19
72°
59°
20
72°
64°
21
61°
55°
22
59°
52°
23
58°
46°
24
64°
39°
25
67°
42°
26
67°
44°
27
68°
47°
28
66°
48°
29
68°
49°
30
69°
52°
1
66°
51°
2
65°
46°
3
63°
51°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Indiana
Indiana's September 2026 forecast shows daily high temperatures ranging from 58° to 69°, with overnight lows between 39° and 55°. The average high for September is 65° 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 Indiana. See also: October | November | December.
