S
M
T
W
T
F
S
30
84°
64°
31
88°
59°
1
85°
63°
2
83°
66°
3
90°
69°
4
89°
68°
5
87°
68°
6
86°
61°
7
79°
63°
8
78°
61°
9
81°
57°
10
78°
55°
11
75°
52°
12
74°
53°
13
74°
54°
14
73°
51°
15
78°
56°
16
75°
53°
17
75°
57°
18
74°
56°
19
73°
53°
20
75°
55°
21
76°
56°
22
76°
56°
23
75°
55°
24
77°
56°
25
76°
55°
26
75°
53°
27
76°
54°
28
76°
53°
29
75°
52°
30
75°
54°
1
74°
54°
2
75°
52°
3
73°
51°
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 90°, with overnight lows between 51° and 69°. The average high for September is 78° with an average low of 57°. 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.
