S
M
T
W
T
F
S
30
87°
66°
31
88°
64°
1
82°
61°
2
83°
63°
3
87°
61°
4
88°
65°
5
88°
65°
6
86°
64°
7
86°
59°
8
81°
58°
9
82°
57°
10
83°
57°
11
83°
58°
12
85°
59°
13
84°
62°
14
85°
58°
15
84°
62°
16
84°
61°
17
82°
54°
18
78°
54°
19
76°
55°
20
76°
60°
21
77°
54°
22
76°
57°
23
77°
58°
24
75°
59°
25
77°
58°
26
80°
59°
27
81°
58°
28
78°
56°
29
75°
56°
30
74°
57°
1
73°
56°
2
74°
50°
3
73°
48°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Westminster
Westminster's September 2026 forecast shows daily high temperatures ranging from 73° to 88°, with overnight lows between 48° and 66°. The average high for September is 81° with an average low of 59°. 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 Westminster. See also: October | November | December.
