S
M
T
W
T
F
S
26
61°
50°
27
70°
48°
28
64°
44°
29
69°
53°
30
71°
47°
1
67°
39°
2
64°
37°
3
67°
29°
4
78°
32°
5
79°
40°
6
70°
61°
7
64°
42°
8
71°
33°
9
76°
40°
10
84°
43°
11
60°
44°
12
73°
38°
13
77°
43°
14
61°
37°
15
74°
33°
16
83°
43°
17
90°
56°
18
93°
57°
19
92°
60°
20
93°
55°
21
86°
56°
22
58°
55°
23
58°
55°
24
71°
63°
25
77°
63°
26
75°
65°
27
79°
62°
28
81°
61°
29
77°
52°
30
70°
50°
31
71°
54°
1
74°
55°
2
78°
55°
3
77°
57°
4
79°
57°
5
81°
56°
6
76°
53°
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 58° to 81°, with overnight lows between 50° and 65°. The average high for May is 75° with an average low of 57°. 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.
