S
M
T
W
T
F
S
26
90°
72°
27
89°
71°
28
87°
71°
29
87°
70°
30
84°
69°
31
80°
69°
1
80°
68°
2
82°
69°
3
86°
69°
4
82°
67°
5
80°
66°
6
79°
65°
7
85°
69°
8
81°
68°
9
85°
69°
10
85°
69°
11
84°
68°
12
85°
69°
13
86°
70°
14
86°
69°
15
83°
69°
16
79°
68°
17
78°
68°
18
80°
67°
19
83°
66°
20
84°
67°
21
76°
57°
22
75°
59°
23
76°
59°
24
75°
63°
25
77°
66°
26
78°
67°
27
77°
68°
28
86°
67°
29
87°
58°
30
83°
57°
31
77°
63°
1
76°
63°
2
76°
62°
3
83°
67°
4
85°
64°
5
84°
56°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
August Weather in Mount Prospect
Mount Prospect's August 2026 forecast shows daily high temperatures ranging from 75° to 90°, with overnight lows between 56° and 72°. The average high for August is 82° with an average low of 66°. 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 Mount Prospect. See also: September | October | November.
