Cardiff Half Marathon returns on Sunday 5 October 2025. The race starts at 9:00am and finishes on the Cardiff Bay waterfront. Organisers expect around 30,000 runners and tens of thousands of supporters in the city centre.
Entries are at record levels for the 2025 edition. The event coincides with increased rail demand from football fixtures. City centre impact will be significant on race day.
Why this year matters
The 2025 race draws a sold-out field. The city centre loop affects commuters, shoppers and businesses. Fan attendance is forecast to exceed previous years.
Core pain points for residents and visitors
Major road closures will cover Cardiff city centre from early morning. Disruption will affect commuters, shoppers and local businesses. Transport capacity is strained by event overlap with football trains.
Event essentials
Date: Sunday 5 October 2025. Start time: 9:00am. Expected finish for elite runners: 9:45am. General finish window: 9:00am to 1:30pm.
Expected runners: ~30,000. Spectators: estimated 50,000+. The route is 13.1 miles through the city centre and Cardiff Bay.
Race route map and key landmarks
The start is on Customhouse Street. The route loops through the city centre, passes Cardiff Castle, calls at St Mary Street and Queen Street. Mile markers are placed every 1 mile.
The finish is on the Cardiff Bay waterfront near the Wales Millennium Centre. The interactive map is published by Cardiff Council and event organisers.
Road closures and affected streets
Closures begin from 5:00am and lift progressively from 2:00pm. Diversion routes are signposted. Drivers should avoid the city centre.
| Road / Area | Closure start | Expected reopen |
|---|---|---|
| Customhouse Street | 05:00 | 14:00 |
| Westgate Street | 06:00 | 13:30 |
| St Mary Street | 06:30 | 13:00 |
| Queen Street | 06:30 | 13:00 |
| Wood Street | 06:00 | 14:00 |
| Working Street | 06:00 | 14:00 |
| Cardiff Bay Barrage | 07:00 | 14:30 |
A full map of Cardiff Half Marathon road closures is available via Wales Online and Cardiff Council.
Travel advice for runners and supporters
Train services to Cardiff Central will run to a Sunday timetable with extra football trains. Hits Radio South Wales reports additional services for event overlap. Allow extra time for boarding.
Bus routes will divert around the closed city centre. Temporary stops will operate on Newport Road and Cowbridge Road East. Service changes are published by Cardiff Bus.
Parking restrictions apply in the city centre and Cardiff Bay from 5:00am. Park and ride sites at Culverhouse Cross and Cardiff Gate remain open. No-parking zones are enforced on the race route.
Spectator guide
Best viewing spots are at Cardiff Castle, City Hall, and the Bay waterfront finish. The Principality Stadium area and civic centre have limited access due to road closures.
Crowd management measures include barriers and stewards. Safety measures are in place along the entire route. Spectators should use public transport.
Tips to avoid disruption
Plan ahead for travel and allow extra time. Alternative routes for drivers are via the A470 and A48. Use public transport and carpooling where possible.
FAQ
Will roads be closed all day? No. Closures start early and lift progressively from early afternoon.
Can I drive into Cardiff city centre on race day? Access is restricted. Expect delays and diversions.
How to get to the start and finish line by train? Cardiff Central is the nearest station. Walk to Customhouse Street and the Bay waterfront.
Where can spectators watch safely? Designated viewing zones at Castle, City Hall and the finish line are recommended.
💡 Frequently Asked Questions (FAQ)
- Q: When is the Cardiff Half Marathon 2025?
- A: Sunday 5 October 2025. Start time is 9:00am with elite finish around 9:45am and general finish window 9:00am to 1:30pm.
- Q: Where does the Cardiff Half Marathon start and finish?
- A: Start is on Customhouse Street in Cardiff city centre. Finish is on the Cardiff Bay waterfront near Wales Millennium Centre.
- Q: Will there be road closures for the race?
- A: Yes. Major road closures will cover Cardiff city centre from early morning on race day, affecting commuters, shoppers and local businesses.
- Q: How many runners and spectators are expected?
- A: Around 30,000 runners are entered, with an estimated 50,000+ spectators in the city centre.
- Q: Will transport be affected by the half marathon?
- A: Yes. Transport capacity is strained by the event overlapping with football fixture rail demand, causing significant disruption in the city centre.
Extended Reading
Cardiff Half Marathon road closures, map and race route. Wales Online. https://www.walesonline.co.uk/sport/other-sport/athletics/cardiff-half-marathon-road-closures-34713275
Travel advice and football trains. Hits Radio South Wales. https://www.hellorayo.co.uk/hits-radio/south-wales/news/cardiff-half-marathon-football-trains
Event coverage and timing. BBC News. https://www.bbc.com/news/articles/cwz0v7mep5xko