S
M
T
W
T
F
S
26
103°
71°
27
93°
73°
28
95°
68°
29
92°
67°
30
96°
65°
31
90°
62°
1
94°
62°
2
102°
75°
3
101°
62°
4
81°
61°
5
85°
60°
6
96°
65°
7
98°
64°
8
101°
65°
9
99°
62°
10
93°
60°
11
95°
61°
12
93°
61°
13
87°
59°
14
84°
58°
15
89°
55°
16
90°
59°
17
89°
57°
18
89°
58°
19
87°
56°
20
85°
56°
21
87°
55°
22
86°
54°
23
86°
55°
24
88°
58°
25
89°
54°
26
85°
55°
27
88°
57°
28
89°
58°
29
88°
57°
30
89°
58°
31
89°
58°
1
88°
57°
2
88°
57°
3
87°
56°
4
85°
56°
5
83°
55°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
August Weather in Mission Viejo
Mission Viejo's August 2026 forecast shows daily high temperatures ranging from 81° to 102°, with overnight lows between 54° and 75°. The average high for August is 90° with an average low of 59°. 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 Mission Viejo. See also: September | October | November.
