S
M
T
W
T
F
S
26
65°
33°
27
72°
35°
28
57°
36°
29
46°
32°
30
44°
33°
1
40°
29°
2
46°
26°
3
54°
27°
4
66°
43°
5
52°
31°
6
51°
32°
7
48°
33°
8
51°
33°
9
50°
36°
10
53°
37°
11
55°
36°
12
56°
39°
13
58°
40°
14
57°
41°
15
58°
40°
16
60°
41°
17
58°
42°
18
65°
45°
19
64°
45°
20
63°
47°
21
66°
41°
22
60°
40°
23
57°
40°
24
58°
39°
25
58°
39°
26
60°
40°
27
61°
40°
28
61°
41°
29
62°
42°
30
64°
46°
31
63°
47°
1
65°
45°
2
66°
46°
3
70°
50°
4
66°
48°
5
68°
53°
6
75°
54°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
May Weather in St.-Charles
St.-Charles's May 2026 forecast shows daily high temperatures ranging from 48° to 75°, with overnight lows between 31° and 54°. The average high for May is 60° with an average low of 42°. 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 St.-Charles. See also: June | July | August.
