S
M
T
W
T
F
S
30
80°
55°
31
86°
49°
1
83°
47°
2
77°
46°
3
76°
48°
4
78°
48°
5
79°
55°
6
85°
56°
7
85°
49°
8
79°
48°
9
76°
46°
10
77°
51°
11
78°
54°
12
85°
44°
13
76°
49°
14
78°
54°
15
85°
54°
16
86°
47°
17
83°
42°
18
72°
47°
19
76°
43°
20
80°
49°
21
79°
50°
22
81°
50°
23
81°
46°
24
80°
45°
25
69°
47°
26
74°
47°
27
78°
46°
28
77°
47°
29
77°
48°
30
78°
46°
1
77°
37°
2
70°
35°
3
64°
34°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Guernsey
Guernsey's September 2026 forecast shows daily high temperatures ranging from 64° to 86°, with overnight lows between 34° and 56°. The average high for September is 78° with an average low of 47°. 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 Guernsey. See also: October | November | December.
