S
M
T
W
T
F
S
30
91°
71°
31
87°
67°
1
86°
63°
2
84°
60°
3
85°
64°
4
87°
64°
5
92°
71°
6
87°
68°
7
93°
66°
8
92°
69°
9
93°
70°
10
92°
68°
11
90°
66°
12
88°
68°
13
84°
66°
14
87°
67°
15
89°
70°
16
88°
64°
17
91°
67°
18
83°
62°
19
84°
63°
20
87°
65°
21
89°
67°
22
87°
66°
23
86°
67°
24
85°
64°
25
85°
66°
26
89°
67°
27
89°
67°
28
88°
66°
29
88°
66°
30
87°
65°
1
88°
66°
2
87°
65°
3
85°
63°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Irwindale
Irwindale's September 2026 forecast shows daily high temperatures ranging from 83° to 93°, with overnight lows between 62° and 71°. The average high for September is 88° with an average low of 66°. 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 Irwindale. See also: October | November | December.
