S
M
T
W
T
F
S
30
69°
59°
31
74°
55°
1
74°
61°
2
75°
66°
3
79°
60°
4
75°
54°
5
71°
52°
6
73°
53°
7
75°
53°
8
69°
52°
9
70°
51°
10
76°
53°
11
68°
53°
12
68°
52°
13
66°
50°
14
65°
49°
15
67°
53°
16
72°
53°
17
69°
48°
18
64°
45°
19
65°
44°
20
72°
53°
21
72°
53°
22
73°
54°
23
73°
51°
24
71°
50°
25
71°
50°
26
72°
52°
27
71°
51°
28
72°
48°
29
65°
44°
30
59°
41°
1
58°
43°
2
64°
49°
3
68°
48°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in De Kalb Junction
De Kalb Junction's September 2026 forecast shows daily high temperatures ranging from 58° to 79°, with overnight lows between 41° and 66°. The average high for September is 70° with an average low of 51°. 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 Junction. See also: October | November | December.