S
M
T
W
T
F
S
26
82°
53°
27
85°
62°
28
79°
61°
29
76°
66°
30
78°
63°
31
84°
59°
1
83°
66°
2
82°
68°
3
79°
67°
4
80°
64°
5
81°
68°
6
80°
67°
7
85°
65°
8
82°
63°
9
83°
66°
10
82°
64°
11
81°
62°
12
79°
61°
13
81°
60°
14
83°
60°
15
78°
58°
16
76°
57°
17
76°
61°
18
77°
60°
19
76°
58°
20
75°
57°
21
76°
62°
22
79°
61°
23
76°
57°
24
75°
56°
25
74°
57°
26
75°
56°
27
74°
55°
28
74°
55°
29
75°
54°
30
74°
56°
31
79°
62°
1
80°
62°
2
79°
61°
3
74°
57°
4
73°
54°
5
72°
53°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
August Weather in Big Island
Big Island's August 2026 forecast shows daily high temperatures ranging from 72° to 85°, with overnight lows between 53° and 68°. The average high for August is 78° with an average low of 60°. 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 Big Island. See also: September | October | November.