S
M
T
W
T
F
S
30
82°
69°
31
78°
71°
1
80°
68°
2
74°
67°
3
88°
69°
4
86°
75°
5
80°
70°
6
77°
66°
7
79°
66°
8
83°
71°
9
83°
73°
10
84°
67°
11
81°
66°
12
77°
68°
13
80°
70°
14
82°
69°
15
79°
67°
16
78°
62°
17
76°
64°
18
76°
64°
19
75°
62°
20
74°
60°
21
76°
64°
22
69°
64°
23
70°
63°
24
70°
63°
25
72°
60°
26
75°
60°
27
71°
56°
28
70°
60°
29
75°
62°
30
76°
62°
1
75°
61°
2
74°
62°
3
73°
59°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Forest Park
Forest Park's September 2026 forecast shows daily high temperatures ranging from 69° to 84°, with overnight lows between 56° and 73°. The average high for September is 76° with an average low of 64°. 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.
