S
M
T
W
T
F
S
26
81°
51°
27
83°
61°
28
66°
55°
29
64°
50°
30
67°
40°
1
64°
44°
2
64°
43°
3
77°
54°
4
77°
58°
5
64°
48°
6
59°
44°
7
61°
46°
8
66°
50°
9
73°
54°
10
72°
55°
11
74°
55°
12
74°
56°
13
76°
58°
14
76°
56°
15
77°
57°
16
80°
62°
17
79°
61°
18
75°
62°
19
79°
61°
20
75°
56°
21
78°
55°
22
72°
54°
23
72°
54°
24
73°
55°
25
71°
55°
26
72°
56°
27
74°
55°
28
75°
60°
29
76°
60°
30
79°
65°
31
76°
63°
1
77°
58°
2
78°
59°
3
79°
62°
4
80°
66°
5
82°
67°
6
80°
68°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
May Weather in Granite City
Granite City's May 2026 forecast shows daily high temperatures ranging from 59° to 82°, with overnight lows between 43° and 68°. The average high for May is 74° 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 Granite City. See also: June | July | August.
