S
M
T
W
T
F
S
30
80°
51°
31
75°
55°
1
75°
59°
2
74°
54°
3
80°
60°
4
82°
55°
5
80°
50°
6
73°
50°
7
73°
48°
8
72°
52°
9
76°
57°
10
75°
49°
11
71°
47°
12
71°
47°
13
72°
50°
14
71°
48°
15
69°
46°
16
69°
46°
17
68°
45°
18
67°
45°
19
67°
46°
20
68°
45°
21
68°
45°
22
69°
48°
23
71°
52°
24
73°
51°
25
74°
54°
26
74°
47°
27
73°
43°
28
65°
50°
29
65°
50°
30
73°
47°
1
70°
50°
2
68°
49°
3
65°
42°
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 65° to 82°, with overnight lows between 42° and 60°. The average high for September is 72° with an average low of 50°. 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.
