S
M
T
W
T
F
S
30
91°
70°
31
92°
69°
1
90°
68°
2
89°
67°
3
88°
66°
4
85°
66°
5
86°
67°
6
89°
67°
7
89°
64°
8
90°
63°
9
90°
62°
10
88°
63°
11
89°
65°
12
88°
64°
13
88°
64°
14
84°
62°
15
88°
63°
16
88°
57°
17
81°
57°
18
81°
58°
19
82°
56°
20
83°
58°
21
86°
61°
22
86°
61°
23
83°
59°
24
83°
59°
25
85°
60°
26
84°
60°
27
83°
59°
28
80°
58°
29
85°
54°
30
83°
56°
1
78°
57°
2
81°
56°
3
76°
57°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Irmo
Irmo's September 2026 forecast shows daily high temperatures ranging from 76° to 92°, with overnight lows between 54° and 70°. The average high for September is 85° with an average low of 62°. 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 Irmo. See also: October | November | December.
