S
M
T
W
T
F
S
26
81°
56°
27
80°
52°
28
83°
54°
29
82°
54°
30
84°
54°
31
85°
52°
1
88°
53°
2
96°
53°
3
91°
54°
4
87°
54°
5
86°
54°
6
80°
52°
7
79°
53°
8
79°
53°
9
84°
53°
10
82°
51°
11
84°
51°
12
81°
53°
13
80°
55°
14
71°
59°
15
74°
55°
16
76°
54°
17
78°
55°
18
78°
53°
19
78°
55°
20
72°
56°
21
73°
55°
22
75°
54°
23
73°
55°
24
69°
55°
25
81°
54°
26
83°
55°
27
84°
53°
28
81°
52°
29
81°
53°
30
82°
54°
31
81°
54°
1
83°
53°
2
82°
55°
3
81°
56°
4
77°
52°
5
79°
53°
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 69° to 84°, with overnight lows between 52° and 56°. The average high for August is 79° 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.
