S
M
T
W
T
F
S
30
88°
71°
31
88°
70°
1
89°
68°
2
82°
63°
3
81°
64°
4
81°
65°
5
82°
62°
6
83°
67°
7
87°
69°
8
87°
68°
9
86°
69°
10
88°
69°
11
88°
68°
12
87°
69°
13
87°
69°
14
87°
62°
15
80°
60°
16
77°
58°
17
78°
59°
18
77°
57°
19
76°
56°
20
76°
56°
21
81°
57°
22
82°
60°
23
82°
55°
24
83°
54°
25
74°
53°
26
75°
55°
27
77°
60°
28
80°
60°
29
80°
52°
30
73°
51°
1
72°
59°
2
73°
58°
3
76°
55°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Mt. Vernon Square
Mt. Vernon Square's September 2026 forecast shows daily high temperatures ranging from 72° to 89°, with overnight lows between 51° and 71°. The average high for September is 81° with an average low of 61°. 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 Mt. Vernon Square. See also: October | November | December.
