S
M
T
W
T
F
S
26
66°
43°
27
73°
53°
28
70°
50°
29
58°
36°
30
51°
34°
1
49°
31°
2
50°
35°
3
53°
41°
4
58°
40°
5
59°
44°
6
59°
45°
7
62°
46°
8
61°
45°
9
62°
39°
10
63°
43°
11
64°
46°
12
68°
49°
13
69°
44°
14
63°
42°
15
62°
41°
16
63°
43°
17
64°
43°
18
65°
51°
19
73°
48°
20
67°
44°
21
66°
44°
22
65°
45°
23
67°
45°
24
74°
55°
25
77°
54°
26
69°
50°
27
67°
46°
28
68°
48°
29
74°
55°
30
78°
56°
31
78°
56°
1
77°
57°
2
80°
58°
3
80°
59°
4
79°
55°
5
71°
51°
6
73°
55°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
May Weather in Cortland
Cortland's May 2026 forecast shows daily high temperatures ranging from 49° to 80°, with overnight lows between 31° and 59°. The average high for May is 67° with an average low of 47°. 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 Cortland. See also: June | July | August.