S
M
T
W
T
F
S
30
89°
66°
31
94°
71°
1
95°
71°
2
95°
71°
3
94°
70°
4
92°
67°
5
85°
64°
6
85°
64°
7
84°
63°
8
88°
63°
9
82°
62°
10
79°
58°
11
80°
58°
12
82°
60°
13
82°
61°
14
81°
62°
15
80°
62°
16
80°
61°
17
79°
61°
18
80°
60°
19
80°
61°
20
81°
61°
21
80°
60°
22
80°
60°
23
79°
59°
24
80°
60°
25
79°
59°
26
80°
57°
27
79°
58°
28
79°
58°
29
78°
57°
30
77°
56°
1
76°
55°
2
76°
55°
3
75°
54°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Indianapolis
Indianapolis's September 2026 forecast shows daily high temperatures ranging from 75° to 95°, with overnight lows between 54° and 71°. The average high for September is 82° with an average low of 61°. 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 Indianapolis. See also: October | November | December.
