S
M
T
W
T
F
S
26
80°
53°
27
83°
62°
28
66°
54°
29
67°
48°
30
66°
41°
1
64°
43°
2
62°
44°
3
75°
42°
4
78°
57°
5
69°
47°
6
64°
44°
7
68°
40°
8
78°
49°
9
82°
56°
10
71°
53°
11
77°
45°
12
82°
51°
13
74°
54°
14
73°
47°
15
82°
54°
16
81°
69°
17
87°
64°
18
79°
65°
19
81°
58°
20
68°
53°
21
73°
59°
22
70°
61°
23
76°
60°
24
77°
60°
25
77°
62°
26
77°
64°
27
80°
63°
28
80°
65°
29
79°
63°
30
82°
63°
31
83°
62°
1
81°
59°
2
83°
63°
3
77°
59°
4
76°
56°
5
79°
63°
6
84°
65°
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 68° to 84°, with overnight lows between 53° and 65°. The average high for May is 78° 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 Collinsville. See also: June | July | August.
