Mont-Blanc - OCC 2026
The forecast arrives five days before the start.
Here you'll find the elevation profile, an estimated finish time based on your UTMB Index and details of the 5 aid stations to plan your nutrition and hydration segment by segment.
What's your time based on your UTMB?
Times estimated by the RAVIT model, learned from real ultra-trail finish times. Enter your UTMB Index (utmb.world) to get a personalized estimate.
Predicted race time based on your UTMB Index® · smoothed times achieved by runners at your level in past editions
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Cut-off times and crew - Mont-Blanc - OCC · 2026
Data from the official race rules, checked for every edition. The race rules prevail. Positions are interpolated along the GPX track and are a guide, not official course marking.
What you'll find at each aid station
| Product | Champex-Lackm 8.4 | Trientkm 24.9 | Col de Balmekm 34.7 | Argentièrekm 50.5 | Chamonixkm 61.5 |
|---|---|---|---|---|---|
| Water | available | available | available | available | available |
| Brand products · Näak | unavailable | available | unavailable | available | unavailable |
| Hot meal | unavailable | unavailable | unavailable | unavailable | available |
Elevation profile
The course and its aid stations
Mont-Blanc - OCC: times, aid-station stops and fuelling needs by UTMB® Index
Between a UTMB® Index of 500 and 800, the estimated finish time on this race runs from 11h30 to 6h43, and the aid-station stop budget from 0h07 to 0h01. The longer the race, the more stops weigh: this is time you should plan to spend standing still, not only running.
SourceBelow a UTMB® Index of roughly 325, the overall cut-off of 14h30 is no longer reachable at the estimated pace.
| UTMB® Index | Estimated time | Of which stops | Night hours | Carbs | Fluid | Sodium | Cut-off margin |
|---|---|---|---|---|---|---|---|
| 500 | 11h30 | 0h07 | — | 690 g | 8.1 L | 5,750 mg | +3h00 |
| 550 | 10h35 | 0h06 | — | 635 g | 7.4 L | 5,292 mg | +3h55 |
| 600 | 9h36 | 0h05 | — | 576 g | 6.7 L | 4,800 mg | +4h54 |
| 650 | 8h51 | 0h04 | — | 531 g | 6.2 L | 4,425 mg | +5h39 |
| 700 | 7h52 | 0h03 | — | 472 g | 5.5 L | 3,933 mg | +6h38 |
| 750 | 7h12 | 0h02 | — | 432 g | 5 L | 3,600 mg | +7h18 |
| 800 | 6h43 | 0h01 | — | 403 g | 4.7 L | 3,358 mg | +7h47 |
Figures based on 60 g of carbohydrate, 700 mL of fluid and 500 mg of sodium per hour, "average" preparation and mild conditions (15–25 °C). Above 25 °C, count on roughly 900 mL/h and 700 mg/h. Carbohydrate intake is trained: 60 g/h is a floor, 90 g/h assumes a glucose-fructose blend and a gut used to it.
Measured on the 2026 edition: the field checkpoint by checkpoint
1,944 starters, 19.6% DNF rate, 7 timed checkpoints.
| Segment | km | Median | Middle half | Measured | Median passage | Still ranked |
|---|---|---|---|---|---|---|
| Start → Champex-Lac | 7.3 | 1 h 08 | 57 min – 1 h 16 | 1,943 | 1 h 05 | 1,944 |
| Champex-Lac → La Giète | 18.8 | 2 h 04 | 1 h 42 – 2 h 24 | 1,867 | 3 h 07 | 1,923 |
| La Giète → Trient | 23.9 | 45 min | 37 min – 54 min | 1,849 | 3 h 49 | 1,905 |
| Trient → Col de Balme | 33.5 | 2 h 56 | 2 h 21 – 3 h 23 | 1,790 | 6 h 39 | 1,791 |
| Col de Balme → TCVallorcine | 41.1 | 1 h 38 | 1 h 20 – 1 h 54 | 1,642 | 8 h 16 | 1,648 |
| TCVallorcine → Argentière | 50.2 | 1 h 29 | 1 h 16 – 1 h 41 | 1,613 | 9 h 47 | 1,618 |
| Argentière → Chamonix | 60.9 | 1 h 39 | 1 h 23 – 1 h 57 | 1,562 | 11 h 24 | 1,563 |
“Median passage” is elapsed time from the start, not a clock time: the clock time depends on the edition.
Where runners drop out. Col de Balme (143) · Trient (114) · Argentière (55) out of 381 total DNFs.
RAVIT record from the official timing of the 2026 edition, data from September 1, 2026.
SourceOther trails worth preparing for
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Sources and method
- Time projection — times by UTMB Index are taken from the actual splits of runners in each level band on previous editions of this race, aid station stops included. No formula is used as long as these results exist.
- Trail nutrition — hourly targets for carbohydrate, fluid and sodium follow the commonly accepted ultra-endurance guidance. La Clinique du Coureur — Fuelling in trail running
- Course, aid stations and cut-offs — taken from the event's official rules, which prevail in case of any discrepancy. Official site — Mont-Blanc - OCC
Weather for Mont-Blanc - OCC
The weather for Mont-Blanc - OCC will appear here as soon as the forecast models reach that date, around five days before the start: feels-like temperature, rain, snow, wind and storms, section by section and at your passage time.
Detailed weather for Mont-Blanc - OCC, hour by hour on the courseFrequently asked questions
How many checkpoints?
Mont-Blanc - OCC has 5 checkpoints: 3 aid stations and 2 water points. Details are in the two tables above.
What's the longest segment without aid?
The one leading to Trient: 16.5 km and 0 m elevation gain. That's the one to load up for first.
How do I find the exact location of an aid station?
The Google Maps icon in the “Access” column opens the aid station's location: handy for planning your crew's routes.
What distance and elevation gain?
Mont-Blanc - OCC is 62 km long with 3525 m of elevation gain.
How long to finish?
With a UTMB Index of 600 (average runner), the estimated time is around 9h36 for Mont-Blanc - OCC.
What's the weather forecast?
The weather for Mont-Blanc - OCC will be published on this page around five days before the start, once the forecast models reach the race date. It will be detailed section by section: feels-like temperature, rain, snow, wind and storms.
Want to stack the odds in your favor for Mont-Blanc - OCC?
In 2 minutes, RAVIT generates your complete plan: segment-by-segment time, carbs, water and sodium at every aid station, printable roadbook.
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