S
M
T
W
T
F
S
26
90°
71°
27
86°
72°
28
88°
70°
29
84°
67°
30
82°
70°
31
83°
69°
1
84°
71°
2
89°
72°
3
90°
71°
4
89°
70°
5
88°
70°
6
89°
71°
7
88°
72°
8
89°
72°
9
90°
70°
10
88°
69°
11
86°
68°
12
88°
70°
13
85°
69°
14
81°
63°
15
80°
62°
16
80°
61°
17
81°
63°
18
81°
67°
19
82°
68°
20
85°
68°
21
84°
67°
22
85°
68°
23
83°
67°
24
88°
62°
25
84°
64°
26
84°
67°
27
82°
65°
28
84°
66°
29
83°
64°
30
80°
63°
31
79°
65°
1
81°
65°
2
79°
58°
3
79°
55°
4
76°
55°
5
76°
56°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
August Weather in Mount Vernon
Mount Vernon's August 2026 forecast shows daily high temperatures ranging from 76° to 90°, with overnight lows between 55° and 72°. The average high for August is 84° 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 August weather will actually feel in Mount Vernon. See also: September | October | November.
