S
M
T
W
T
F
S
30
83°
54°
31
79°
66°
1
92°
69°
2
76°
67°
3
87°
69°
4
82°
61°
5
78°
56°
6
77°
53°
7
77°
55°
8
81°
58°
9
83°
64°
10
82°
58°
11
78°
54°
12
74°
55°
13
75°
56°
14
72°
53°
15
75°
52°
16
72°
56°
17
74°
48°
18
72°
46°
19
77°
48°
20
78°
53°
21
77°
54°
22
77°
54°
23
74°
51°
24
73°
48°
25
74°
49°
26
75°
54°
27
73°
51°
28
66°
47°
29
65°
45°
30
66°
44°
1
64°
42°
2
64°
45°
3
65°
41°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Northumberland
Northumberland's September 2026 forecast shows daily high temperatures ranging from 64° to 87°, with overnight lows between 41° and 69°. The average high for September is 74° 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 Northumberland. See also: October | November | December.
