S
M
T
W
T
F
S
28
81°
54°
29
81°
55°
30
77°
55°
1
77°
53°
2
78°
56°
3
84°
55°
4
85°
54°
5
69°
57°
6
75°
56°
7
73°
55°
8
80°
55°
9
86°
56°
10
78°
57°
11
88°
59°
12
89°
53°
13
96°
56°
14
96°
55°
15
95°
54°
16
96°
53°
17
92°
53°
18
94°
52°
19
90°
53°
20
89°
54°
21
90°
55°
22
91°
55°
23
91°
54°
24
90°
55°
25
90°
55°
26
89°
54°
27
88°
53°
28
86°
52°
29
89°
53°
30
89°
54°
31
88°
54°
1
88°
53°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
July Weather in Port Costa
Port Costa's July 2026 forecast shows daily high temperatures ranging from 73° to 96°, with overnight lows between 52° and 59°. The average high for July is 89° 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 July weather will actually feel in Port Costa. See also: August | September | October.
