S
M
T
W
T
F
S
30
101°
76°
31
101°
79°
1
99°
77°
2
96°
75°
3
85°
75°
4
93°
73°
5
96°
76°
6
100°
77°
7
98°
77°
8
100°
75°
9
99°
77°
10
99°
75°
11
95°
74°
12
93°
74°
13
92°
73°
14
90°
69°
15
93°
73°
16
92°
72°
17
93°
73°
18
93°
73°
19
92°
72°
20
92°
72°
21
91°
71°
22
89°
71°
23
88°
70°
24
90°
71°
25
89°
70°
26
90°
69°
27
91°
70°
28
91°
70°
29
90°
69°
30
90°
69°
1
89°
68°
2
89°
69°
3
88°
69°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Duncanville
Duncanville's September 2026 forecast shows daily high temperatures ranging from 85° to 100°, with overnight lows between 68° and 77°. The average high for September is 93° with an average low of 72°. 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 Duncanville. See also: October | November | December.