S
M
T
W
T
F
S
26
57°
42°
27
68°
45°
28
65°
49°
29
62°
48°
30
60°
47°
1
64°
46°
2
61°
49°
3
59°
45°
4
72°
50°
5
81°
59°
6
71°
55°
7
64°
49°
8
63°
46°
9
65°
52°
10
73°
52°
11
61°
53°
12
66°
46°
13
72°
54°
14
66°
53°
15
66°
50°
16
80°
55°
17
87°
66°
18
88°
71°
19
93°
73°
20
92°
66°
21
66°
55°
22
68°
56°
23
57°
49°
24
56°
50°
25
73°
55°
26
82°
66°
27
84°
65°
28
76°
60°
29
77°
60°
30
74°
54°
31
74°
57°
1
75°
58°
2
71°
57°
3
74°
60°
4
74°
61°
5
82°
66°
6
82°
66°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
May Weather in Prospect Heights
Prospect Heights's May 2026 forecast shows daily high temperatures ranging from 71° to 84°, with overnight lows between 54° and 66°. The average high for May is 77° 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 May weather will actually feel in Prospect Heights. See also: June | July | August.
