S
M
T
W
T
F
S
30
73°
63°
31
72°
59°
1
72°
57°
2
70°
63°
3
79°
66°
4
70°
59°
5
73°
55°
6
81°
59°
7
77°
64°
8
64°
57°
9
66°
54°
10
67°
59°
11
72°
55°
12
73°
62°
13
73°
60°
14
75°
62°
15
71°
53°
16
67°
56°
17
67°
57°
18
66°
54°
19
68°
55°
20
70°
55°
21
71°
55°
22
69°
56°
23
69°
50°
24
68°
49°
25
65°
47°
26
65°
47°
27
66°
50°
28
65°
44°
29
60°
42°
30
60°
43°
1
59°
47°
2
64°
48°
3
63°
48°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in London
London's September 2026 forecast shows daily high temperatures ranging from 59° to 75°, with overnight lows between 42° and 62°. The average high for September is 67° 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 London. See also: October | November | December.