S
M
T
W
T
F
S
30
89°
71°
31
89°
70°
1
90°
70°
2
91°
69°
3
91°
70°
4
90°
72°
5
91°
73°
6
89°
71°
7
88°
69°
8
91°
72°
9
92°
70°
10
91°
71°
11
92°
70°
12
91°
69°
13
91°
68°
14
89°
69°
15
89°
69°
16
85°
68°
17
86°
69°
18
Hist. Avg.
86°
67°
19
Hist. Avg.
86°
66°
20
Hist. Avg.
86°
66°
21
Hist. Avg.
86°
66°
22
Hist. Avg.
86°
66°
23
Hist. Avg.
86°
65°
24
Hist. Avg.
85°
65°
25
Hist. Avg.
85°
65°
26
Hist. Avg.
85°
64°
27
Hist. Avg.
84°
64°
28
Hist. Avg.
84°
64°
29
Hist. Avg.
84°
63°
30
Hist. Avg.
84°
63°
1
Hist. Avg.
83°
63°
2
Hist. Avg.
83°
62°
3
Hist. Avg.
83°
62°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
*Temporarily Unavailable
September Weather in Forest Park
Forest Park's September 2026 forecast shows daily high temperatures ranging from 85° to 92°, with overnight lows between 68° and 73°. The average high for September is 90° with an average low of 70°. 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 Forest Park. See also: October | November | December.
