S
M
T
W
T
F
S
30
90°
71°
31
93°
70°
1
96°
72°
2
96°
72°
3
97°
73°
4
97°
73°
5
96°
72°
6
98°
74°
7
94°
72°
8
92°
69°
9
92°
71°
10
89°
71°
11
86°
70°
12
88°
70°
13
86°
71°
14
89°
72°
15
88°
71°
16
87°
69°
17
86°
67°
18
84°
65°
19
83°
64°
20
83°
66°
21
82°
62°
22
86°
66°
23
85°
67°
24
85°
66°
25
84°
66°
26
85°
65°
27
85°
66°
28
84°
66°
29
83°
65°
30
84°
65°
1
84°
64°
2
82°
62°
3
73°
57°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Rockford
Rockford's September 2026 forecast shows daily high temperatures ranging from 73° to 92°, with overnight lows between 57° and 72°. The average high for September is 85° with an average low of 67°. 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 Rockford. See also: October | November | December.
