S
M
T
W
T
F
S
30
95°
71°
31
94°
72°
1
94°
72°
2
93°
71°
3
94°
70°
4
94°
70°
5
92°
71°
6
93°
69°
7
92°
69°
8
91°
68°
9
91°
67°
10
90°
68°
11
92°
69°
12
92°
69°
13
93°
70°
14
85°
69°
15
87°
68°
16
Hist. Avg.
87°
62°
17
Hist. Avg.
87°
62°
18
Hist. Avg.
86°
61°
19
Hist. Avg.
86°
61°
20
Hist. Avg.
86°
60°
21
Hist. Avg.
85°
60°
22
Hist. Avg.
85°
60°
23
Hist. Avg.
85°
59°
24
Hist. Avg.
84°
58°
25
Hist. Avg.
84°
58°
26
Hist. Avg.
84°
58°
27
Hist. Avg.
83°
57°
28
Hist. Avg.
83°
57°
29
Hist. Avg.
83°
56°
30
Hist. Avg.
82°
56°
1
Hist. Avg.
82°
55°
2
Hist. Avg.
82°
55°
3
Hist. Avg.
81°
55°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
*Temporarily Unavailable
September Weather in Mount Vernon
Mount Vernon's September 2026 forecast shows daily high temperatures ranging from 85° to 95°, with overnight lows between 67° and 72°. The average high for September is 92° with an average low of 70°. 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 Vernon. See also: October | November | December.
