S
M
T
W
T
F
S
30
72°
55°
31
71°
54°
1
71°
55°
2
70°
55°
3
71°
52°
4
70°
50°
5
65°
52°
6
67°
54°
7
68°
51°
8
67°
52°
9
68°
53°
10
69°
49°
11
68°
49°
12
68°
50°
13
67°
49°
14
66°
53°
15
67°
48°
16
64°
47°
17
63°
46°
18
63°
51°
19
65°
50°
20
64°
49°
21
62°
46°
22
63°
47°
23
63°
50°
24
62°
48°
25
62°
48°
26
64°
49°
27
63°
50°
28
66°
52°
29
66°
49°
30
Hist. Avg.
61°
49°
1
Hist. Avg.
61°
49°
2
Hist. Avg.
61°
49°
3
Hist. Avg.
61°
49°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
*Temporarily Unavailable
September Weather in Cardiff
Cardiff's September 2026 forecast shows daily high temperatures ranging from 62° to 72°, with overnight lows between 46° and 55°. The average high for September is 66° with an average low of 50°. 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 Cardiff. See also: October | November | December.
