S
M
T
W
T
F
S
30
83°
69°
31
87°
71°
1
95°
77°
2
96°
78°
3
91°
77°
4
93°
76°
5
81°
72°
6
79°
68°
7
80°
63°
8
86°
72°
9
79°
63°
10
78°
61°
11
81°
64°
12
83°
65°
13
80°
66°
14
80°
61°
15
75°
59°
16
72°
57°
17
76°
60°
18
75°
60°
19
76°
56°
20
74°
55°
21
73°
60°
22
69°
60°
23
71°
59°
24
77°
60°
25
77°
60°
26
76°
59°
27
76°
60°
28
78°
60°
29
77°
61°
30
77°
60°
1
74°
54°
2
70°
48°
3
62°
45°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in River Grove
River Grove's September 2026 forecast shows daily high temperatures ranging from 62° to 86°, with overnight lows between 45° and 72°. 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 River Grove. See also: October | November | December.
