S
M
T
W
T
F
S
30
82°
59°
31
79°
69°
1
88°
68°
2
73°
68°
3
85°
68°
4
84°
70°
5
79°
65°
6
77°
61°
7
77°
52°
8
79°
60°
9
84°
68°
10
82°
62°
11
78°
54°
12
76°
58°
13
80°
61°
14
81°
61°
15
80°
60°
16
76°
57°
17
77°
56°
18
77°
57°
19
76°
56°
20
75°
53°
21
78°
58°
22
71°
58°
23
71°
57°
24
72°
57°
25
71°
56°
26
76°
56°
27
74°
53°
28
74°
55°
29
75°
56°
30
76°
56°
1
75°
55°
2
74°
55°
3
74°
53°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Downingtown
Downingtown's September 2026 forecast shows daily high temperatures ranging from 71° to 84°, with overnight lows between 52° and 68°. The average high for September is 76° with an average low of 57°. 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 Downingtown. See also: October | November | December.
