S
M
T
W
T
F
S
30
62°
53°
31
68°
52°
1
69°
54°
2
64°
53°
3
61°
51°
4
63°
47°
5
67°
54°
6
71°
53°
7
65°
54°
8
68°
53°
9
69°
52°
10
66°
53°
11
60°
51°
12
75°
51°
13
75°
50°
14
67°
51°
15
71°
52°
16
77°
51°
17
76°
53°
18
77°
52°
19
75°
50°
20
71°
52°
21
70°
50°
22
69°
49°
23
69°
52°
24
70°
51°
25
66°
45°
26
62°
48°
27
61°
46°
28
62°
46°
29
60°
47°
30
60°
44°
1
61°
46°
2
59°
43°
3
59°
42°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Duncan
Duncan's September 2026 forecast shows daily high temperatures ranging from 59° to 77°, with overnight lows between 42° and 53°. The average high for September is 68° with an average low of 49°. 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 Duncan. See also: October | November | December.
