S
M
T
W
T
F
S
30
78°
56°
31
76°
55°
1
76°
56°
2
77°
57°
3
75°
60°
4
76°
56°
5
78°
56°
6
77°
55°
7
76°
54°
8
75°
53°
9
75°
54°
10
74°
56°
11
74°
53°
12
74°
53°
13
74°
52°
14
76°
55°
15
76°
58°
16
78°
57°
17
74°
51°
18
72°
50°
19
72°
51°
20
74°
56°
21
72°
50°
22
71°
52°
23
76°
55°
24
75°
56°
25
76°
55°
26
75°
47°
27
74°
48°
28
68°
47°
29
67°
46°
30
68°
46°
1
67°
46°
2
Hist. Avg.
69°
47°
3
Hist. Avg.
69°
47°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in West Chester
West Chester's September 2026 forecast shows daily high temperatures ranging from 67° to 78°, with overnight lows between 46° and 60°. The average high for September is 74° with an average low of 53°. 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 West Chester. See also: October | November | December.
