S
M
T
W
T
F
S
26
84°
55°
27
84°
55°
28
84°
56°
29
83°
55°
30
82°
54°
31
82°
52°
1
82°
54°
2
83°
55°
3
82°
54°
4
85°
56°
5
84°
57°
6
85°
57°
7
85°
56°
8
84°
57°
9
85°
57°
10
86°
56°
11
85°
53°
12
84°
52°
13
83°
51°
14
79°
51°
15
79°
53°
16
82°
54°
17
84°
56°
18
85°
56°
19
85°
53°
20
84°
55°
21
85°
56°
22
85°
56°
23
83°
52°
24
80°
51°
25
81°
52°
26
79°
52°
27
79°
51°
28
80°
50°
29
80°
51°
30
83°
54°
31
85°
55°
1
85°
53°
2
86°
54°
3
86°
52°
4
85°
56°
5
85°
55°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
August Weather in Mill Valley
Mill Valley's August 2026 forecast shows daily high temperatures ranging from 79° to 86°, with overnight lows between 50° and 57°. The average high for August is 83° with an average low of 54°. 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 Mill Valley. See also: September | October | November.
