Cardiff Weather in September
18.2°C high · 10.7°C low · 97 mm rain · 4.9h sun
Sep is a warm month in Cardiff — not peak season, but a good time to avoid crowds.
September at a glance
| Metric | Value |
|---|---|
| Average high | 18.2°C |
| Average low | 10.7°C |
| Rainfall | 97 mm |
| Sunshine | 4.9 hours/day |
| Daylight | 12.4 hours |
What to pack in September
Pack a jacket and layers, plus a raincoat and umbrella for Cardiff in September.
Cardiff weather by month
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Frequently asked questions
What is the weather in Cardiff in September?
Highs of 18.2°C and lows of 10.7°C, with about 97 mm of rain and 4.9 hours of sunshine per day.
Is September a good time to visit Cardiff?
Sep is a warm month in Cardiff — not peak season, but a good time to avoid crowds.
What to do in Cardiff · Best time to visit Cardiff
Climate data: Open-Meteo Historical (ERA5), 1991–2020. CC BY 4.0.