S
M
T
W
T
F
S
30
66°
55°
31
64°
54°
1
64°
55°
2
65°
55°
3
63°
54°
4
63°
55°
5
64°
54°
6
62°
52°
7
66°
50°
8
66°
54°
9
65°
54°
10
65°
53°
11
67°
52°
12
67°
51°
13
66°
50°
14
66°
52°
15
65°
51°
16
65°
51°
17
64°
49°
18
65°
51°
19
64°
53°
20
65°
52°
21
64°
53°
22
63°
51°
23
64°
49°
24
64°
50°
25
62°
50°
26
61°
51°
27
62°
52°
28
61°
49°
29
63°
48°
30
61°
48°
1
62°
49°
2
58°
49°
3
58°
51°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Newcastle
Newcastle's September 2026 forecast shows daily high temperatures ranging from 58° to 67°, with overnight lows between 48° and 55°. The average high for September is 64° with an average low of 52°. 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 Newcastle. See also: October | November | December.