S
M
T
W
T
F
S
26
63°
32°
27
61°
33°
28
61°
27°
29
48°
38°
30
53°
38°
1
54°
41°
2
58°
36°
3
48°
33°
4
56°
37°
5
56°
38°
6
55°
46°
7
60°
40°
8
55°
31°
9
57°
29°
10
55°
45°
11
62°
46°
12
56°
37°
13
56°
36°
14
66°
44°
15
66°
38°
16
72°
38°
17
79°
46°
18
66°
44°
19
63°
47°
20
85°
46°
21
62°
35°
22
64°
29°
23
62°
27°
24
65°
29°
25
55°
46°
26
77°
48°
27
N/A
28
51°
42°
29
52°
39°
30
50°
36°
31
58°
38°
1
59°
43°
2
56°
45°
3
64°
42°
4
70°
45°
5
72°
45°
6
68°
48°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
*Temporarily Unavailable
May Weather in Mount Prospect
Mount Prospect's May 2026 forecast shows daily high temperatures ranging from 50° to 72°, with overnight lows between 36° and 48°. The average high for May is 60° with an average low of 42°. AccuWeather's monthly forecast extends further ahead than any other source, with day-by-day RealFeel® Temperatures giving a complete picture of how May weather will actually feel in Mount Prospect. See also: June | July | August.
