S
M
T
W
T
F
S
30
82°
65°
31
76°
65°
1
77°
64°
2
79°
59°
3
76°
58°
4
75°
56°
5
75°
56°
6
76°
59°
7
80°
61°
8
83°
63°
9
83°
62°
10
82°
63°
11
74°
53°
12
74°
53°
13
75°
52°
14
73°
51°
15
74°
55°
16
75°
51°
17
73°
52°
18
72°
51°
19
73°
48°
20
70°
48°
21
70°
49°
22
71°
48°
23
71°
49°
24
72°
55°
25
76°
57°
26
73°
56°
27
69°
55°
28
75°
52°
29
69°
46°
30
70°
52°
1
69°
55°
2
76°
42°
3
77°
42°
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 69° to 83°, with overnight lows between 42° and 65°. The average high for September is 75° with an average low of 54°. 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.
