S
M
T
W
T
F
S
26
85°
68°
27
86°
67°
28
85°
69°
29
86°
67°
30
85°
68°
31
84°
67°
1
78°
64°
2
77°
62°
3
78°
66°
4
80°
67°
5
81°
67°
6
84°
66°
7
85°
67°
8
85°
67°
9
84°
66°
10
84°
67°
11
83°
67°
12
85°
66°
13
84°
68°
14
87°
59°
15
84°
60°
16
79°
62°
17
80°
63°
18
84°
61°
19
83°
58°
20
78°
56°
21
76°
56°
22
76°
58°
23
77°
58°
24
77°
57°
25
78°
62°
26
76°
60°
27
83°
58°
28
83°
57°
29
76°
56°
30
74°
56°
31
75°
57°
1
74°
56°
2
74°
55°
3
75°
55°
4
75°
56°
5
76°
58°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
August Weather in Lake Forest
Lake Forest's August 2026 forecast shows daily high temperatures ranging from 74° to 87°, with overnight lows between 55° and 69°. The average high for August is 80° with an average low of 62°. 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 Lake Forest. See also: September | October | November.
