S
M
T
W
T
F
S
30
81°
68°
31
87°
70°
1
93°
73°
2
94°
73°
3
91°
70°
4
94°
70°
5
84°
65°
6
82°
62°
7
82°
65°
8
85°
66°
9
86°
65°
10
80°
59°
11
79°
58°
12
83°
61°
13
80°
58°
14
79°
59°
15
80°
57°
16
75°
53°
17
78°
58°
18
71°
57°
19
76°
58°
20
76°
57°
21
75°
57°
22
75°
55°
23
71°
55°
24
73°
53°
25
76°
55°
26
76°
50°
27
65°
45°
28
64°
43°
29
65°
46°
30
64°
43°
1
63°
45°
2
66°
51°
3
65°
50°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Carpentersville
Carpentersville's September 2026 forecast shows daily high temperatures ranging from 63° to 94°, with overnight lows between 43° and 70°. The average high for September is 76° with an average low of 56°. 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 Carpentersville. See also: October | November | December.