S
M
T
W
T
F
S
26
56°
41°
27
70°
36°
28
63°
44°
29
62°
50°
30
71°
47°
1
67°
40°
2
62°
49°
3
63°
43°
4
80°
45°
5
89°
58°
6
71°
60°
7
62°
50°
8
73°
42°
9
76°
52°
10
87°
49°
11
62°
47°
12
71°
40°
13
78°
55°
14
64°
53°
15
72°
52°
16
87°
51°
17
88°
58°
18
95°
63°
19
97°
72°
20
96°
69°
21
73°
57°
22
59°
52°
23
57°
52°
24
66°
62°
25
78°
63°
26
78°
64°
27
78°
68°
28
83°
59°
29
79°
57°
30
75°
54°
31
71°
56°
1
72°
55°
2
75°
57°
3
77°
61°
4
79°
62°
5
80°
63°
6
81°
60°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
May Weather in Saint Charles
Saint Charles's May 2026 forecast shows daily high temperatures ranging from 66° to 83°, with overnight lows between 54° and 68°. The average high for May is 77° 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 Saint Charles. See also: June | July | August.
