S
M
T
W
T
F
S
26
85°
68°
27
87°
69°
28
89°
69°
29
87°
68°
30
87°
67°
31
80°
67°
1
83°
66°
2
88°
69°
3
89°
70°
4
89°
69°
5
90°
69°
6
87°
68°
7
85°
66°
8
84°
63°
9
84°
60°
10
79°
59°
11
80°
61°
12
79°
59°
13
79°
59°
14
80°
58°
15
78°
62°
16
79°
63°
17
85°
61°
18
79°
59°
19
79°
57°
20
81°
59°
21
82°
61°
22
82°
62°
23
84°
64°
24
84°
64°
25
85°
63°
26
86°
63°
27
85°
55°
28
81°
55°
29
76°
56°
30
75°
54°
31
76°
53°
1
75°
54°
2
75°
52°
3
74°
51°
4
75°
53°
5
77°
57°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
August Weather in Crystal Lake
Crystal Lake's August 2026 forecast shows daily high temperatures ranging from 74° to 90°, with overnight lows between 51° and 70°. The average high for August is 82° with an average low of 61°. 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 Crystal Lake. See also: September | October | November.
