S
M
T
W
T
F
S
30
81°
69°
31
91°
72°
1
94°
77°
2
96°
78°
3
92°
79°
4
93°
78°
5
83°
73°
6
82°
65°
7
80°
65°
8
86°
71°
9
83°
65°
10
79°
61°
11
80°
62°
12
82°
65°
13
79°
62°
14
73°
61°
15
73°
58°
16
75°
59°
17
75°
58°
18
74°
60°
19
75°
55°
20
76°
61°
21
73°
60°
22
69°
60°
23
71°
59°
24
76°
60°
25
77°
60°
26
76°
59°
27
76°
60°
28
77°
60°
29
77°
61°
30
76°
60°
1
74°
54°
2
69°
48°
3
62°
45°
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 62° to 86°, with overnight lows between 45° and 71°. The average high for September is 76° with an average low of 60°. 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.
