S
M
T
W
T
F
S
26
89°
54°
27
88°
53°
28
86°
52°
29
89°
53°
30
89°
54°
31
88°
54°
1
88°
53°
2
89°
54°
3
87°
53°
4
85°
52°
5
84°
52°
6
83°
51°
7
83°
52°
8
86°
52°
9
85°
51°
10
85°
50°
11
82°
48°
12
82°
49°
13
83°
49°
14
82°
50°
15
83°
49°
16
82°
50°
17
84°
49°
18
86°
49°
19
86°
49°
20
85°
48°
21
85°
48°
22
86°
52°
23
84°
52°
24
85°
49°
25
85°
50°
26
84°
49°
27
85°
49°
28
84°
50°
29
83°
48°
30
85°
48°
31
89°
49°
1
89°
51°
2
84°
47°
3
82°
47°
4
83°
48°
5
83°
49°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
August Weather in Port Costa
Port Costa's August 2026 forecast shows daily high temperatures ranging from 82° to 89°, with overnight lows between 47° and 54°. The average high for August is 85° with an average low of 50°. 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 Port Costa. See also: September | October | November.
