S
M
T
W
T
F
S
30
102°
76°
31
100°
75°
1
101°
75°
2
102°
75°
3
99°
73°
4
102°
73°
5
100°
75°
6
102°
75°
7
102°
73°
8
102°
77°
9
102°
79°
10
88°
72°
11
100°
70°
12
106°
73°
13
102°
77°
14
100°
77°
15
102°
77°
16
100°
77°
17
100°
75°
18
99°
73°
19
99°
72°
20
95°
73°
21
91°
68°
22
90°
70°
23
95°
68°
24
94°
68°
25
94°
69°
26
93°
69°
27
93°
69°
28
95°
73°
29
89°
69°
30
82°
66°
1
80°
61°
2
82°
63°
3
85°
58°
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 80° to 95°, with overnight lows between 58° and 73°. The average high for September is 89° with an average low of 67°. 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.
