S
M
T
W
T
F
S
26
89°
70°
27
84°
71°
28
81°
62°
29
80°
58°
30
84°
57°
31
78°
65°
1
72°
66°
2
77°
63°
3
83°
59°
4
85°
62°
5
81°
66°
6
80°
67°
7
85°
64°
8
82°
64°
9
84°
61°
10
87°
71°
11
81°
67°
12
82°
69°
13
77°
65°
14
82°
67°
15
79°
70°
16
85°
67°
17
81°
65°
18
79°
62°
19
83°
62°
20
82°
58°
21
82°
59°
22
82°
63°
23
77°
57°
24
76°
55°
25
77°
62°
26
80°
60°
27
77°
58°
28
79°
60°
29
80°
64°
30
82°
66°
31
78°
56°
1
77°
56°
2
74°
58°
3
76°
55°
4
78°
57°
5
77°
58°
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 82°, with overnight lows between 55° and 66°. The average high for August is 78° 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 Crystal Lake. See also: September | October | November.
