S
M
T
W
T
F
S
26
73°
53°
27
73°
49°
28
61°
45°
29
60°
41°
30
68°
39°
1
67°
36°
2
66°
34°
3
81°
50°
4
84°
51°
5
62°
46°
6
61°
42°
7
73°
43°
8
67°
48°
9
85°
42°
10
71°
52°
11
81°
43°
12
84°
58°
13
80°
47°
14
81°
53°
15
90°
62°
16
91°
63°
17
84°
67°
18
84°
52°
19
66°
47°
20
66°
48°
21
66°
58°
22
72°
55°
23
76°
58°
24
84°
61°
25
87°
63°
26
82°
64°
27
80°
58°
28
79°
61°
29
80°
59°
30
79°
58°
31
83°
64°
1
83°
63°
2
81°
63°
3
75°
58°
4
76°
58°
5
81°
64°
6
79°
64°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
May Weather in Effingham
Effingham's May 2026 forecast shows daily high temperatures ranging from 66° to 87°, with overnight lows between 47° and 67°. The average high for May is 78° with an average low of 59°. 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 Effingham. See also: June | July | August.