S
M
T
W
T
F
S
30
90°
68°
31
86°
64°
1
84°
64°
2
80°
66°
3
87°
70°
4
88°
69°
5
89°
70°
6
87°
65°
7
79°
64°
8
78°
62°
9
77°
59°
10
78°
57°
11
74°
53°
12
76°
54°
13
74°
55°
14
73°
52°
15
78°
58°
16
75°
55°
17
75°
58°
18
77°
57°
19
74°
54°
20
75°
56°
21
77°
57°
22
77°
57°
23
76°
56°
24
77°
57°
25
76°
56°
26
75°
56°
27
76°
55°
28
76°
55°
29
75°
54°
30
74°
56°
1
74°
56°
2
73°
54°
3
73°
52°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Winthrop
Winthrop's September 2026 forecast shows daily high temperatures ranging from 73° to 89°, with overnight lows between 52° and 70°. The average high for September is 77° with an average low of 58°. AccuWeather's monthly forecast extends further ahead than any other source, with day-by-day RealFeel® Temperatures giving a complete picture of how September weather will actually feel in Winthrop. See also: October | November | December.
