Races Half marathon · Caernarfon, UK
Caernarfon Half Marathon
Caernarfon Half Marathon is a rolling half marathon in Caernarfon, UK, held each September. The race starts and finishes beside Caernarfon Castle. The organiser describes a route with a few small climbs and some long, fast downhill sections. Early September in north-west Wales is mild with a chance of showers, typically 11 to 18°C. The rises around Caernarfon are small but relentless — train on similar terrain and race by effort, not pace.
Page rebuilt 2026-11-14 · race facts not independently verified — confirm dates and entries on the official race site
When
September
next: Sunday 5 September 2027
Course
rolling
Half marathon
Conditions
Early September in north-west Wales is mild with a chance of showers, typically 11 to 18°C.
Racing this course well
The race starts and finishes beside Caernarfon Castle. The organiser describes a route with a few small climbs and some long, fast downhill sections.
The rises around Caernarfon are small but relentless — train on similar terrain and race by effort, not pace.
Getting a place
Official Caernarfon Half Marathon site →Checked November 2026
Race day
- Next race
- Sunday 5 September 2027
- Start time
- 10:00
The course in numbers
- Layout
- Loop
- Surface
- Road, with some but not all roads closed to traffic
Pick your goal for Caernarfon
Pace charts, weekly structure and timelines for the most common half marathon goals:
The date shown is the one the organiser has announced. Change it if yours differs.
Build your training around Caernarfon Half Marathon.
RunV works backwards from race day to today. Your plan adapts when life interrupts, and you approve every change. 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 Caernarfon Half Marathon?
- The next Caernarfon Half Marathon is on Sunday 5 September 2027 in Caernarfon, UK. It is held each September.
- Is the Caernarfon Half Marathon course flat?
- The race starts and finishes beside Caernarfon Castle. The organiser describes a route with a few small climbs and some long, fast downhill sections.
- How should I train for the Caernarfon Half Marathon?
- Build for the course you'll actually race at the Caernarfon Half Marathon: rolling terrain, September conditions. RunV Premium builds a training plan around your goal time and race date, and lets you adapt it when life interrupts the Caernarfon build.
Not sure what to target? Predict your half marathon time from a recent race →
More half marathon races
Supplements research for this distance
Build for Caernarfon — around your actual life
RunV engineers your block backwards from race day in September — and adapts it when training doesn't go to script. You approve every change.
