S
M
T
W
T
F
S
26
80°
60°
27
80°
60°
28
79°
59°
29
79°
58°
30
72°
54°
31
70°
51°
1
70°
51°
2
71°
54°
3
73°
57°
4
78°
58°
5
76°
57°
6
74°
58°
7
75°
57°
8
73°
56°
9
71°
55°
10
71°
49°
11
75°
55°
12
77°
56°
13
79°
57°
14
80°
56°
15
76°
55°
16
75°
56°
17
80°
49°
18
73°
48°
19
69°
47°
20
68°
46°
21
69°
46°
22
70°
47°
23
72°
46°
24
73°
46°
25
75°
47°
26
76°
54°
27
76°
51°
28
71°
47°
29
67°
51°
30
71°
52°
31
73°
46°
1
74°
43°
2
68°
44°
3
67°
46°
4
72°
53°
5
71°
49°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
August Weather in Grand Valley
Grand Valley's August 2026 forecast shows daily high temperatures ranging from 67° to 80°, with overnight lows between 43° and 60°. The average high for August is 74° with an average low of 52°. 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 Grand Valley. See also: September | October | November.
