S
M
T
W
T
F
S
30
83°
65°
31
82°
68°
1
88°
69°
2
92°
73°
3
87°
69°
4
84°
66°
5
81°
58°
6
81°
60°
7
80°
61°
8
83°
67°
9
82°
64°
10
76°
55°
11
75°
55°
12
74°
56°
13
77°
59°
14
76°
56°
15
79°
58°
16
78°
51°
17
76°
55°
18
72°
54°
19
76°
56°
20
76°
57°
21
75°
56°
22
72°
54°
23
71°
50°
24
72°
53°
25
75°
54°
26
74°
52°
27
64°
47°
28
63°
45°
29
63°
48°
30
62°
45°
1
61°
43°
2
63°
46°
3
67°
50°
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 61° to 87°, with overnight lows between 43° and 69°. The average high for September is 74° with an average low of 55°. 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.
