S
M
T
W
T
F
S
26
81°
55°
27
81°
55°
28
71°
59°
29
80°
61°
30
68°
51°
1
66°
45°
2
68°
44°
3
68°
37°
4
78°
39°
5
78°
45°
6
76°
64°
7
69°
49°
8
71°
45°
9
73°
49°
10
81°
55°
11
77°
51°
12
75°
50°
13
79°
50°
14
73°
44°
15
78°
40°
16
82°
48°
17
91°
56°
18
87°
64°
19
89°
63°
20
88°
62°
21
81°
67°
22
78°
67°
23
78°
65°
24
77°
67°
25
79°
68°
26
76°
67°
27
80°
66°
28
79°
67°
29
78°
66°
30
77°
62°
31
76°
61°
1
77°
62°
2
77°
62°
3
79°
63°
4
81°
64°
5
90°
67°
6
78°
61°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
May Weather in Collinsville
Collinsville's May 2026 forecast shows daily high temperatures ranging from 76° to 90°, with overnight lows between 61° and 68°. The average high for May is 79° with an average low of 65°. 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 Collinsville. See also: June | July | August.
