S
M
T
W
T
F
S
30
80°
61°
31
81°
61°
1
81°
60°
2
80°
60°
3
80°
52°
4
73°
49°
5
71°
57°
6
72°
59°
7
78°
59°
8
80°
57°
9
79°
58°
10
74°
57°
11
77°
55°
12
77°
58°
13
76°
58°
14
76°
57°
15
77°
56°
16
76°
48°
17
71°
56°
18
73°
52°
19
71°
49°
20
70°
46°
21
64°
44°
22
64°
52°
23
65°
49°
24
64°
45°
25
63°
44°
26
62°
44°
27
63°
51°
28
70°
50°
29
69°
44°
30
62°
44°
1
61°
46°
2
60°
40°
3
59°
41°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Willsboro
Willsboro's September 2026 forecast shows daily high temperatures ranging from 59° to 81°, with overnight lows between 40° and 61°. The average high for September is 71° 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 September weather will actually feel in Willsboro. See also: October | November | December.
