S
M
T
W
T
F
S
26
76°
58°
27
74°
54°
28
70°
50°
29
64°
44°
30
65°
42°
1
59°
40°
2
60°
43°
3
68°
48°
4
66°
49°
5
65°
48°
6
65°
50°
7
69°
52°
8
68°
51°
9
72°
52°
10
66°
48°
11
66°
55°
12
75°
53°
13
68°
48°
14
67°
48°
15
67°
49°
16
68°
50°
17
69°
51°
18
75°
59°
19
77°
60°
20
75°
60°
21
75°
59°
22
77°
60°
23
78°
61°
24
80°
62°
25
81°
61°
26
75°
56°
27
73°
56°
28
75°
57°
29
78°
59°
30
81°
62°
31
82°
63°
1
83°
64°
2
83°
64°
3
82°
65°
4
83°
65°
5
81°
64°
6
82°
66°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
May Weather in Mattoon
Mattoon's May 2026 forecast shows daily high temperatures ranging from 59° to 83°, with overnight lows between 40° and 66°. The average high for May is 73° with an average low of 55°. 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 Mattoon. See also: June | July | August.
