Races Half marathon · Cardiff, UK
Cardiff Half Marathon
Cardiff Half Marathon is a flat half marathon in Cardiff, UK, held each October. Fast, flat capital-city loop past the castle, the bay and Roath Park. Early October in South Wales is mild, 8-14C, with a fair chance of rain. The Cardiff Half Marathon's flat profile means your pacing discipline, not the terrain, decides the day.
Page rebuilt 2026-10-02 · race facts not independently verified — confirm dates and entries on the official race site
When
October
every year
Course
flat
Half marathon
Conditions
Early October in South Wales is mild, 8-14C, with a fair chance of rain.
Racing this course well
Fast, flat capital-city loop past the castle, the bay and Roath Park.
The Cardiff Half Marathon's flat profile means your pacing discipline, not the terrain, decides the day.
Pick your goal for Cardiff
Pace charts, weekly structure and timelines for the most common half marathon goals:
We don’t hold a confirmed date for this edition, so any countdown comes from the date you enter here.
Build your training around Cardiff Half Marathon.
RunV works backwards from race day to today and rearranges the weeks when life interrupts. It does not adapt to this specific course — the pacing guidance above is where the course knowledge is.
Everything above stays free and complete — this is an optional next step, not a paywall.
Asked often
- When is the Cardiff Half Marathon?
- It is held each October in Cardiff, UK. Check the official Cardiff Half Marathon site for the exact date and entry windows.
- Is the Cardiff Half Marathon course flat?
- Fast, flat capital-city loop past the castle, the bay and Roath Park.
- How should I train for the Cardiff Half Marathon?
- Build for the course you'll actually race at the Cardiff Half Marathon: flat terrain, October conditions. RunV generates a plan for your goal time and rebuilds it every time life interrupts the Cardiff build.
Not sure what to target? Predict your half marathon time from a recent race →
More half marathon races
Build for Cardiff — around your actual life
RunV engineers your block backwards from race day in October — and rebuilds it every time training doesn't go to script.
