S
M
T
W
T
F
S
28
72°
64°
29
72°
63°
30
73°
65°
1
74°
66°
2
74°
66°
3
73°
67°
4
75°
67°
5
74°
65°
6
73°
65°
7
74°
64°
8
73°
64°
9
72°
62°
10
71°
61°
11
69°
62°
12
69°
62°
13
70°
63°
14
71°
62°
15
71°
64°
16
73°
66°
17
74°
66°
18
75°
65°
19
75°
68°
20
74°
69°
21
76°
69°
22
76°
68°
23
75°
67°
24
76°
67°
25
76°
68°
26
75°
70°
27
76°
70°
28
74°
69°
29
75°
65°
30
70°
66°
31
71°
68°
1
73°
67°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
July Weather in Costa Mesa
Costa Mesa's July 2026 forecast shows daily high temperatures ranging from 69° to 76°, with overnight lows between 61° and 70°. The average high for July is 73° with an average low of 66°. 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 Costa Mesa. See also: August | September | October.
