S
M
T
W
T
F
S
26
86°
65°
27
89°
71°
28
89°
70°
29
90°
64°
30
87°
61°
31
84°
63°
1
82°
64°
2
80°
63°
3
82°
64°
4
87°
65°
5
90°
66°
6
89°
67°
7
88°
66°
8
87°
64°
9
88°
67°
10
85°
67°
11
87°
67°
12
85°
66°
13
85°
67°
14
87°
66°
15
83°
66°
16
83°
64°
17
84°
66°
18
82°
66°
19
85°
65°
20
86°
65°
21
83°
63°
22
82°
62°
23
85°
65°
24
88°
63°
25
82°
58°
26
84°
65°
27
88°
66°
28
89°
66°
29
88°
65°
30
88°
64°
31
87°
61°
1
79°
60°
2
79°
57°
3
80°
59°
4
85°
63°
5
83°
64°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
August Weather in Cornwall
Cornwall's August 2026 forecast shows daily high temperatures ranging from 79° to 90°, with overnight lows between 57° and 71°. The average high for August is 85° with an average low of 64°. 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 Cornwall. See also: September | October | November.
