Cardiff Weather in September

Mild and comfortable, with some rainy days. Average highs of 18°C and lows of 12°C, with around 12 rainy days expected throughout the month.

While September isn't our top-rated month for Cardiff, it has its own appeal — typically lower prices, fewer crowds, and a more local feel.

Average high

18°C

Average low

12°C

Rainy days

12 days

Best months to visit

Year-round

What to do in Cardiff in September

Whatever the weather, Cardiff rewards curious visitors. Here are some of the best ways to spend your time:

Tour Cardiff Castle from Roman times Visit the National Museum Cardiff (free) Explore the Victorian and Edwardian shopping arcades Walk Bute Park and see Cathays Park's government buildings Day trip to nearby Caerphilly Castle Catch rugby at the Millennium Stadium

What to pack for September

Layer up — a mid-weight jacket, jumpers, and comfortable trousers. Waterproof shoes are recommended. Scarves and gloves may be useful in the evenings.