S
M
T
W
T
F
S
30
65°
41°
31
65°
37°
1
68°
37°
2
69°
34°
3
71°
37°
4
72°
34°
5
75°
38°
6
N/A
7
71°
48°
8
71°
49°
9
76°
50°
10
75°
51°
11
67°
49°
12
68°
46°
13
65°
44°
14
64°
43°
15
64°
48°
16
67°
47°
17
66°
47°
18
64°
46°
19
64°
44°
20
61°
33°
21
63°
38°
22
59°
34°
23
60°
37°
24
59°
37°
25
56°
32°
26
57°
32°
27
60°
36°
28
55°
33°
29
56°
26°
30
47°
23°
1
47°
22°
2
48°
22°
3
49°
23°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
*Temporarily Unavailable
September Weather in Jefferson
Jefferson's September 2026 forecast shows daily high temperatures ranging from 47° to 76°, with overnight lows between 22° and 51°. The average high for September is 61° with an average low of 39°. 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 Jefferson. See also: October | November | December.