Ultramarathon

TDS

TDS crosses 145 kilometres from Courmayeur through the Aosta Valley and Beaufortain with 9,500 metres of climbing before Chamonix in late August.

Next raceMonday, August 24, 2026
Distance categoryUltramarathon
LocationCourmayeur, Italy
Get alertsLast checked August 4, 2026

Quick facts

  • 145 kilometres with 9,500 metres of climbing
  • Courmayeur-to-Chamonix point-to-point route
  • Maximum time of 44 hours 55 minutes
  • Night start during UTMB Mont-Blanc week
Race-day forecast

TDS race-day forecast

Rain on race day · 12-24°C (54-75°F) · 48% rain · 4 mph wind

Race-day forecast for Monday, August 24, 2026 in Courmayeur, Aosta Valley, IT. Checked 8:59 PM GMT+2 race-local time. Data: Open-Meteo.

About the TDS

TDS is UTMB Mont-Blanc week's rugged alternative to the flagship loop. Its own start in Courmayeur, 145-kilometre route and nearly 45-hour limit support a separate race guide and results identity.

Course

The point-to-point Alpine course gains about 9,500 metres while crossing the Aosta Valley, Savoie and Beaufortain toward Chamonix. Technical passes and long descents demand mountain experience.

Race-day weather

Late-August Alpine weather can swing from hot valleys to freezing rain, wind or storms on high passes. Night sections add another temperature cycle to an already exposed course.

Past TDS dates and results

YearDateStatusResults
2026Monday, August 24, 2026Upcoming

TDS FAQ

When is the TDS?

The 2026 TDS is on Monday, August 24, 2026.

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