S
M
T
W
T
F
S
30
80°
69°
31
88°
72°
1
93°
71°
2
93°
71°
3
89°
69°
4
89°
70°
5
88°
68°
6
83°
64°
7
78°
61°
8
80°
60°
9
80°
59°
10
77°
55°
11
75°
54°
12
74°
53°
13
74°
56°
14
77°
61°
15
79°
60°
16
80°
60°
17
78°
59°
18
79°
59°
19
79°
60°
20
80°
60°
21
80°
59°
22
79°
59°
23
79°
58°
24
78°
58°
25
79°
57°
26
77°
58°
27
78°
57°
28
77°
56°
29
76°
56°
30
76°
55°
1
75°
55°
2
76°
54°
3
75°
54°
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 74° to 93°, with overnight lows between 53° and 71°. The average high for September is 80° 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 Rockford. See also: October | November | December.
