S
M
T
W
T
F
S
26
55°
43°
27
58°
44°
28
52°
43°
29
50°
45°
30
56°
46°
1
65°
47°
2
56°
44°
3
56°
44°
4
65°
49°
5
71°
55°
6
65°
52°
7
57°
44°
8
57°
41°
9
58°
48°
10
60°
52°
11
61°
49°
12
58°
50°
13
59°
52°
14
62°
51°
15
65°
50°
16
69°
55°
17
70°
54°
18
70°
55°
19
69°
54°
20
65°
55°
21
65°
55°
22
66°
54°
23
66°
52°
24
62°
51°
25
64°
51°
26
65°
57°
27
66°
54°
28
65°
52°
29
66°
51°
30
65°
54°
31
67°
58°
1
70°
57°
2
69°
54°
3
68°
58°
4
71°
59°
5
68°
58°
6
68°
59°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
May Weather in Winthrop
Winthrop's May 2026 forecast shows daily high temperatures ranging from 56° to 71°, with overnight lows between 41° and 59°. The average high for May is 65° with an average low of 52°. 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 Winthrop. See also: June | July | August.