S
M
T
W
T
F
S
30
91°
69°
31
91°
68°
1
90°
68°
2
91°
67°
3
85°
62°
4
85°
62°
5
84°
63°
6
86°
66°
7
85°
64°
8
87°
66°
9
90°
66°
10
86°
63°
11
85°
61°
12
87°
66°
13
89°
60°
14
88°
58°
15
82°
58°
16
83°
57°
17
82°
58°
18
83°
59°
19
87°
62°
20
88°
63°
21
88°
63°
22
85°
62°
23
83°
62°
24
83°
60°
25
84°
58°
26
85°
58°
27
85°
60°
28
84°
60°
29
85°
59°
30
86°
59°
1
86°
58°
2
85°
59°
3
85°
53°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in De Kalb
De Kalb's September 2026 forecast shows daily high temperatures ranging from 82° to 91°, with overnight lows between 53° and 69°. The average high for September is 86° with an average low of 62°. 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 De Kalb. See also: October | November | December.
