S
M
T
W
T
F
S
28
70°
63°
29
71°
64°
30
70°
63°
1
71°
63°
2
73°
64°
3
71°
62°
4
72°
62°
5
72°
64°
6
71°
64°
7
72°
64°
8
73°
64°
9
75°
64°
10
77°
67°
11
75°
67°
12
78°
67°
13
73°
68°
14
76°
69°
15
80°
71°
16
82°
70°
17
80°
69°
18
79°
68°
19
74°
68°
20
75°
66°
21
73°
65°
22
77°
69°
23
77°
68°
24
70°
64°
25
73°
66°
26
76°
68°
27
76°
69°
28
75°
69°
29
76°
68°
30
77°
69°
31
77°
69°
1
76°
68°
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 70° to 82°, with overnight lows between 64° and 71°. The average high for July is 76° with an average low of 68°. 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.
