S
M
T
W
T
F
S
26
102°
75°
27
102°
73°
28
104°
75°
29
102°
77°
30
102°
77°
31
108°
77°
1
95°
73°
2
95°
70°
3
100°
68°
4
102°
72°
5
102°
75°
6
102°
77°
7
100°
73°
8
106°
72°
9
102°
72°
10
101°
76°
11
102°
76°
12
101°
76°
13
102°
77°
14
102°
76°
15
101°
76°
16
103°
72°
17
104°
74°
18
102°
73°
19
104°
75°
20
104°
73°
21
103°
74°
22
101°
75°
23
92°
70°
24
97°
76°
25
96°
75°
26
97°
76°
27
97°
76°
28
96°
75°
29
97°
75°
30
96°
74°
31
95°
73°
1
95°
75°
2
94°
75°
3
95°
74°
4
94°
73°
5
92°
74°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
August Weather in Duncan
Duncan's August 2026 forecast shows daily high temperatures ranging from 92° to 104°, with overnight lows between 70° and 77°. The average high for August is 99° with an average low of 75°. AccuWeather's monthly forecast extends further ahead than any other source, with day-by-day RealFeel® Temperatures giving a complete picture of how August weather will actually feel in Duncan. See also: September | October | November.