S
M
T
W
T
F
S
30
81°
61°
31
81°
61°
1
80°
56°
2
74°
54°
3
72°
53°
4
73°
53°
5
73°
52°
6
77°
57°
7
80°
59°
8
79°
59°
9
76°
58°
10
77°
59°
11
80°
59°
12
80°
58°
13
79°
60°
14
79°
50°
15
72°
50°
16
69°
50°
17
71°
49°
18
77°
55°
19
78°
57°
20
78°
56°
21
75°
50°
22
76°
46°
23
67°
47°
24
66°
50°
25
67°
53°
26
71°
54°
27
73°
53°
28
73°
53°
29
72°
52°
30
73°
53°
1
73°
51°
2
72°
44°
3
71°
42°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Mount Kisco
Mount Kisco's September 2026 forecast shows daily high temperatures ranging from 66° to 81°, with overnight lows between 42° and 61°. The average high for September is 75° with an average low of 54°. 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 Mount Kisco. See also: October | November | December.