S
M
T
W
T
F
S
30
66°
59°
31
64°
57°
1
66°
59°
2
66°
61°
3
64°
59°
4
66°
59°
5
64°
57°
6
72°
58°
7
65°
54°
8
62°
52°
9
62°
53°
10
64°
57°
11
64°
54°
12
63°
56°
13
65°
56°
14
66°
55°
15
64°
52°
16
63°
52°
17
63°
52°
18
64°
54°
19
62°
54°
20
64°
55°
21
65°
55°
22
65°
54°
23
64°
54°
24
65°
53°
25
62°
51°
26
61°
50°
27
63°
47°
28
62°
49°
29
62°
53°
30
61°
52°
1
62°
52°
2
63°
51°
3
63°
53°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Caernarfon
Caernarfon's September 2026 forecast shows daily high temperatures ranging from 61° to 72°, with overnight lows between 47° and 58°. The average high for September is 64° with an average low of 53°. 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 Caernarfon. See also: October | November | December.
