S
M
T
W
T
F
S
26
66°
38°
27
69°
42°
28
71°
47°
29
75°
46°
30
78°
47°
1
79°
46°
2
82°
54°
3
89°
51°
4
86°
53°
5
85°
56°
6
87°
61°
7
83°
60°
8
76°
54°
9
79°
46°
10
74°
45°
11
74°
48°
12
80°
50°
13
73°
51°
14
77°
45°
15
70°
41°
16
69°
39°
17
73°
42°
18
76°
45°
19
77°
46°
20
73°
45°
21
74°
45°
22
73°
41°
23
66°
37°
24
67°
38°
25
67°
42°
26
65°
40°
27
66°
39°
28
66°
38°
29
68°
42°
30
69°
41°
31
68°
40°
1
68°
42°
2
71°
42°
3
74°
45°
4
78°
47°
5
78°
47°
6
77°
48°
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 65° to 80°, with overnight lows between 37° and 51°. The average high for May is 72° with an average low of 43°. 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.