Cardiff Half Marathon
Race Day Weather
Cool temps, strategic wind shifts
Runners will face temperatures rising from 55°F at the start to a peak of 62°F, with humidity at 77%. Wind will start as a headwind in Mile 1, shifting to a crosswind, and then a tailwind in Mile 5. Runners should adjust their pacing for the headwind early and utilize the tailwind for a strong push in the middle miles.
Pace Calculator
Enter a finish time to see what race day does to it.
Get forecast alerts for Cardiff Half Marathon
We'll text or email you when the forecast shifts — so you can adjust gear, pacing, and strategy. Max one per day.
Get your personalized Cardiff Half Marathon race plan
A mile-by-mile breakdown of where your time goes, weather-adjusted splits, fueling timeline with aid stations, packing checklist, carb tracker, spectator guide, all built around your goal and race-day conditions.
Race Info
The Cardiff Half Marathon is held on a Sunday in early October in Cardiff, Wales, and carries a World Athletics Elite Label. The course starts on Castle Street outside Cardiff Castle, runs past the Principality Stadium and Cardiff City Stadium to Penarth Marina and the Cardiff Bay barrage, passes the Senedd and Wales Millennium Centre, then loops Roath Park Lake before finishing on King Edward VII Avenue in the Civic Centre. Cardiff hosted the 2016 IAAF World Half Marathon Championships, and the course records are 59:22 for men (Yismaw Dillu, 2025) and 1:05:40 for women (Joyciline Jepkosgei, 2026).
