S
M
T
W
T
F
S
30
80°
56°
31
79°
56°
1
69°
60°
2
74°
61°
3
76°
61°
4
81°
63°
5
73°
58°
6
73°
51°
7
80°
54°
8
80°
55°
9
79°
55°
10
85°
64°
11
77°
51°
12
77°
46°
13
69°
62°
14
72°
47°
15
71°
43°
16
79°
60°
17
77°
66°
18
77°
47°
19
67°
50°
20
65°
51°
21
66°
51°
22
65°
49°
23
67°
53°
24
69°
51°
25
69°
49°
26
67°
50°
27
73°
50°
28
71°
51°
29
69°
45°
30
65°
44°
1
64°
47°
2
71°
47°
3
64°
49°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Lancaster
Lancaster's September 2026 forecast shows daily high temperatures ranging from 64° to 79°, with overnight lows between 44° and 66°. The average high for September is 69° with an average low of 51°. 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 Lancaster. See also: October | November | December.