S
M
T
W
T
F
S
26
83°
62°
27
89°
62°
28
82°
68°
29
80°
64°
30
68°
59°
1
61°
51°
2
70°
43°
3
74°
45°
4
78°
53°
5
81°
62°
6
79°
55°
7
72°
49°
8
71°
53°
9
73°
58°
10
76°
58°
11
81°
60°
12
82°
58°
13
81°
60°
14
82°
59°
15
84°
63°
16
84°
62°
17
85°
64°
18
84°
64°
19
84°
63°
20
85°
64°
21
85°
64°
22
84°
63°
23
80°
65°
24
81°
65°
25
82°
64°
26
80°
65°
27
80°
64°
28
82°
61°
29
85°
65°
30
86°
64°
31
85°
64°
1
85°
63°
2
87°
67°
3
88°
67°
4
88°
66°
5
83°
63°
6
83°
64°
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 61° to 88°, with overnight lows between 43° and 67°. The average high for May is 81° with an average low of 60°. 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.
