When to walk the Tour du Mont Blanc
The season is set by the huts, not the snow: roughly mid-June to mid-September. Within that window the differences between June, August and September are large enough to change the walk entirely.
| When | What to expect |
|---|---|
| Mid-June | Huts open in stages. Snow still possible on the Bonhomme, the Col des Fours and the Grand Col Ferret. Empty paths, high streams. |
| July | Everything open. Long days, flowers, frequent afternoon thunderstorms. Busy from mid-month. |
| August | Peak, especially around the 15th. Huts booked out months ahead. Hot in the valleys, pleasant high up. |
| Early September | The best compromise: often settled weather, fewer people, everything still open. UTMB race week fills Chamonix and Courmayeur. |
| Mid-September | Huts start closing one by one — check each. Superb light, cold nights. |
| Out of season | Huts shut, cols under snow, reduced transport. A different undertaking entirely. |
Snow on the cols
The Tour crosses eleven cols and tops out at 2531 m on the Grand Col Ferret. Snow lingers on the north-facing approaches well into summer — the Col du Bonhomme and the Col des Fours are the usual culprits, and the Fenêtre d'Arpette is frequently impassable for walkers until well into July. This is not a reason to avoid June; it is a reason to ask the warden every single evening what tomorrow's col is doing, and to accept the lower alternative when the answer is bad.
Weather patterns
Summer in the massif follows a fairly reliable rhythm: clear mornings, cloud building from midday, thunderstorms in the late afternoon. The practical consequence is simple and it is the single most useful habit on this trail — be over the col by lunchtime. Cols are exposed, there is no shelter, and lightning on the Bonhomme or the Grand Col Ferret is a genuine hazard rather than an inconvenience.
The UTMB week
In late August the Ultra-Trail du Mont-Blanc sends thousands of runners round essentially this route. Chamonix and Courmayeur are full, accommodation prices rise, and sections of trail are busy with runners and support. If you want a quiet Tour, avoid that week specifically; if you find it exciting, it is a remarkable thing to walk into.
The short answer
Early September if you can choose freely: settled weather, thinner crowds, all the huts still open, and the light on the Jorasses at its best. Late June if you prefer emptiness and can handle snow. July and August if school holidays decide for you — in which case book in the autumn and read the booking guide first.
Plan around your dates
Set your start date in the planner and it shows the hut availability for exactly those nights, plus a daily weather briefing once you are walking.
Open the planner →