S
M
T
W
T
F
S
30
82°
55°
31
82°
56°
1
68°
61°
2
73°
63°
3
77°
62°
4
85°
64°
5
78°
61°
6
74°
51°
7
82°
47°
8
80°
52°
9
73°
52°
10
86°
68°
11
77°
51°
12
78°
44°
13
67°
61°
14
72°
47°
15
72°
43°
16
80°
51°
17
78°
61°
18
78°
58°
19
63°
49°
20
59°
43°
21
69°
52°
22
67°
43°
23
65°
41°
24
68°
42°
25
69°
40°
26
66°
57°
27
59°
56°
28
57°
54°
29
67°
55°
30
70°
57°
1
76°
56°
2
85°
63°
3
70°
47°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Londonderry
Londonderry's September 2026 forecast shows daily high temperatures ranging from ° to °, with overnight lows between ° and °. The average high for September is ° with an average low of °. 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 Londonderry. See also: October | November | December.
