The Course: New Routes, Old Hills
For its fifth running, the race has scrapped its previous layouts entirely: organisers describe all-new routes for all three distances — Half 21.4km, Mini 10km and Fun Run 5km — with every route officially measured and certified by World Athletics in cooperation with AIMS. [1]
Despite the redesign, the half marathon keeps the character that past editions were known for. Race materials describe the 21k route as "the route is mostly flat with long undulating hills," a description that has carried over from the 2023, 2024 and 2025 editions. [2]
The shorter distances lean easier: the Mini is billed as mostly flat with some sections on dirt and no real slopes, while the Fun Run is framed explicitly as a walk-run route built to pass by temple sights within the Wat La Harn Rai grounds, with no inclines to speak of. [2]
Conditions: Racing Into Rayong's Wet Season
A September date puts this race squarely in Rayong's rainy season peak — historically the wettest month of the year in the province, with heavy downpours and elevated humidity typical of the period. [5]
Average September humidity in the area sits high, and while the region's daytime highs aren't the province's hottest of the year, the combination of rain risk and thick, tropical air means runners should plan for a sticky, potentially soggy morning rather than crisp, dry racing weather. [5]
Organisation and Logistics
The event is run by Yim Yok Yai Co., Ltd. under an explicitly charitable banner: proceeds after costs go toward casting a Buddha statue, Phra Buddha Suwannaphanwichit, and toward commemorating the anniversary of the passing of Luang Pu Tim Isariko, the venerated former abbot of Wat La Harn Rai. [1]
Standard entry includes a race shirt, medal, bib and chip timing, with the finisher shirt handed out after crossing the line; a VIP tier adds a VIP shirt, medal and bib along with a personalised souvenir bearing the runner's name and an image of Luang Pu Tim. [1]
Bib collection runs through a REPC process requiring a registration tracking number or barcode plus ID, and representatives can collect on a runner's behalf with the right documentation. [2]
Awards use gun time for the overall male and female rankings and chip time for age-group placings, but age-category trophies are only handed out if at least one competitor is registered in that group — and results, once posted, are final. [2] Runners who arrive late also get a clear (if blunt) rule: if you start after the sweeper has left the start point by 15 minutes, you're on your own, since there's no sweeper support left on course. [2]
Field Size and Atmosphere
The race appears to be building a following across its recent editions, drawing a solid regional turnout, though exact field sizes are hard to confirm from the public results pages. [3][4]
That growth points to a race building genuine local following rather than one coasting on a single big draw, though it remains a regional Thai event rather than an internationally stacked field. The temple setting and the explicit merit-making framing — donations toward the statue project, remembrance of Luang Pu Tim — give it a devotional, community atmosphere that's distinct from a typical closed-road city race. [1]
Should You Run It?
If you want a well-organised provincial Thai half marathon with a genuine cultural and charitable backbone, newly certified courses, and a field that's clearly expanding each year, this is a reasonable pick — especially if you're already touring temples in Rayong. [1][3][4]
If you're chasing a flat, fast time in cool weather, look elsewhere: the half's undulating profile and September's wet-season humidity work against a PB attempt. [2][5]
Registration for the 2026 fifth edition is open, with entry priced from 550 to 2,000 THB depending on distance and tier, so check the official listing for the category that suits you. [1]