S
M
T
W
T
F
S
26
83°
63°
27
83°
65°
28
85°
64°
29
85°
62°
30
84°
61°
31
78°
58°
1
80°
59°
2
79°
60°
3
80°
59°
4
79°
60°
5
81°
64°
6
82°
62°
7
81°
64°
8
84°
65°
9
81°
65°
10
81°
64°
11
79°
63°
12
84°
64°
13
84°
64°
14
83°
63°
15
84°
59°
16
82°
61°
17
78°
57°
18
79°
57°
19
78°
58°
20
77°
61°
21
79°
63°
22
82°
64°
23
83°
63°
24
82°
59°
25
82°
58°
26
82°
61°
27
81°
57°
28
Hist. Avg.
79°
58°
29
Hist. Avg.
79°
58°
30
Hist. Avg.
78°
57°
31
Hist. Avg.
78°
57°
1
Hist. Avg.
78°
57°
2
Hist. Avg.
78°
57°
3
Hist. Avg.
78°
56°
4
Hist. Avg.
77°
56°
5
Hist. Avg.
77°
56°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
*Temporarily Unavailable
August Weather in Cohasset
Cohasset's August 2026 forecast shows daily high temperatures ranging from 77° to 85°, with overnight lows between 57° and 65°. The average high for August is 81° with an average low of 61°. 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 Cohasset. See also: September | October | November.