S
M
T
W
T
F
S
26
82°
60°
27
88°
63°
28
64°
52°
29
69°
48°
30
70°
48°
1
70°
47°
2
71°
48°
3
85°
48°
4
82°
63°
5
70°
51°
6
68°
47°
7
73°
42°
8
83°
53°
9
84°
52°
10
71°
52°
11
80°
45°
12
82°
53°
13
84°
61°
14
84°
69°
15
88°
71°
16
87°
71°
17
89°
72°
18
90°
65°
19
74°
60°
20
75°
60°
21
78°
61°
22
81°
61°
23
82°
65°
24
82°
67°
25
81°
66°
26
81°
67°
27
82°
62°
28
86°
67°
29
86°
67°
30
84°
66°
31
83°
68°
1
79°
67°
2
79°
68°
3
85°
69°
4
87°
69°
5
87°
68°
6
86°
69°
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 74° to 90°, with overnight lows between 60° and 72°. The average high for May is 83° with an average low of 66°. 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.
