August is one of our busiest months on the Tour du Mont Blanc, so we’ve had plenty of our guides and groups out on the trail. This gives us a good picture of how TMB conditions have developed since July, and what hikers can expect during the second half of the summer.

We’re a team of local guides living around the Mont Blanc massif, and our observations come from days out guiding the TMB in August 2026. We share these reports to help fellow hikers prepare for their own TMB adventure.

A note on timing: we’re updating this report throughout August, so conditions can change quickly. The information below reflects what we’ve seen so far this month.

Disclaimer: Mountain conditions can change quickly, especially at higher altitudes. Use your own judgement and adapt your plans accordingly. If you’re not using a qualified guide, make sure you know how to adjust your itinerary if conditions change. For more information on how to shorten TMB days, read this article.

Overview: August TMB Conditions

August can be very busy and very hot, so our guides often aim to get going before the crowds and the heat. Cristina sums it up nicely:

“I like to leave early, before sunrise, to avoid the crowds and the heat. I ask the refuges to leave us breakfast and coffee out, and we’re leaving by about 5 AM.”

For some stages, an early start really can make the difference between a cool, peaceful morning on the trail and a hot, crowded climb later in the day. Cristina has left as early as 4AM, which sounds dramatic! But it is worth it when you have the cols to yourself and fantastic sunrise views. For tips on hiking in the heat, read this article.

August 2026 has continued the pattern we saw in July: hot, dry and very much summer.

The snow has disappeared from the high passes, and we’re seeing typical summer trail conditions across the route. The bigger challenge this year is the prolonged lack of rain. Météo-France reported in mid-August that soils across France had reached their driest level since measurements began.

Switzerland and Italy are experiencing the same problem. By the start of August, water shortages were affecting rivers, lakes and groundwater.

For TMB conditions, this means water is something to take seriously. Some fountains and natural sources are unreliable, and you shouldn’t assume that every water source marked on an old map will still be running.

August TMB Conditions: Our Notes

We’ve organised our observations in the same order that most people hike the Tour du Mont Blanc. You can see the typical TMB itinerary here.

TMB Conditions in France

Across the French section, TMB conditions have remained dry, sunny and snow-free, with some very hot days. The biggest challenge is still the heat, particularly on exposed climbs. On hot days, start early and aim to get the biggest climbs done before the afternoon heat builds. These include Col du Bonhomme, Col de la Seigne and Grand Col Ferret

Les Houches & Les Contamines

The lower sections of the TMB remain summery. The trails are quite dry, the strawberries have gone, but you’ll still see some meadow flowers

The heat can be particularly noticeable lower down, so don’t underestimate the temperature just because you’re hiking in the mountains.

Lifts : As always in August, the Bellevue lift is running!

Food / Drink : Likewise, all the refuges / buvettes are open. Our favourite is Chalet Miage, which serve delicious blueberry tarts. However, make sure to book a table if you want to eat lunch.

Water sources : Chalet Miage is the best place to fill up on water. There is a water fountain behind the refuge that is free to use.

Col du Bonhomme & Col de la Croix du Bonhomme

The trails around the Col du Bonhomme and Col de la Croix du Bonhomme remain snow-free and dry. Look out for specialised alpine flowers, such as trumpet gentians, which will soon be finished.

The climb up is long and exposed. Start early if temperatures are high and if rain is expected. You’ll be much happier climbing the Col du Bonhomme before the sun reaches its full strength!

Water sources : The fountain outside the refuge dried up in July. Last month, hikers were able to fill up in the refuge, but the refuge is now closed. It’s therefore important to carry plenty of water on this section! You can normally refill your bottles at the Le Balme chalets.

Les Chapieux & Col de la Seigne

The route from Les Chapieux towards the Col de la Seigne is snow-free. There are still a few alpine flowers up high!

Water sources : there is a fairly reliable fountain outside Refuge le Mottes. You could also stop in and buy a bottle.

TMB Conditions in Italy

The Italian section remains hot, dry and snow-free. The higher sections can still feel surprisingly cool when the wind gets up, so keep an extra layer in your pack. The contrast between the hot valleys and cooler high passes can be quite dramatic! Keep your eye out for gentians, and take time to eat a few blueberries!

Courmayeur & Val Ferret

The climb out of Courmayeur towards Rifugio Bertone remains dry and dusty.

It’s a steep climb straight out of town, and on a hot day it can feel much harder than the distance suggests. Set off early if the forecast is hot, when the lower part of the climb is still relatively cool.

The higher trails towards Bonatti and through Val Ferret are in good summer condition. The rhododendrons are almost finished, but they’re still splashing the hillsides with vibrant pink.

Col de la Seigne & Rifugio Elisabetta

TMB conditions around Col de la Seigne and Rifugio Elisabetta are snow-free.

The high altitude means temperatures can drop quickly when the wind picks up, so don’t leave your warm layer at the bottom of your pack.

Water source : there is a fountain near the old buildings / alpage, shortly before Rifugio Elisabetta. This is still running.

Grand Col Ferret

The Grand Col Ferret is also completely snow-free and in summer condition. Again, this is a long climb so an early start really pays off.

Water source: Rifugio Elena is the main reliable place to fill up before the climb.

TMB Conditions in Switzerland

The Swiss section is also snow-free and in full summer condition, but water has become an increasingly important consideration.

Grand Col Ferret to La Fouly

The trail from Grand Col Ferret down towards La Fouly remains in good condition.

However, Switzerland is experiencing a significant water deficit this summer, so don’t rely on every natural spring or small stream. This is really one of the most important point in August TMB conditions reports. Carry plenty of water and fill up whenever you reach a reliable source.

TMB CONDITIONS : La Fouly Trail Closure

The river trail near La Fouly remains closed because of the risk of falling rocks.

However, the new route is clearly marked and has been in place since 11 July. Do not use the old trail! Follow the signed diversion instead. The alternative adds only around five minutes to the route.

This is a good example of why it’s worth checking current TMB conditions before setting off. Trail closures can happen at any point during the season, and the official diversions are usually well marked.

Fenêtre d’Arpette

The snow on the descent down to Champex has now melted.

As always, this is a demanding variant rather than the standard TMB. The boulder sections become much less appealing in wet weather, so check the forecast carefully before choosing Arpette over Bovine. We had two guided groups doing this challenging variant this month!

Water source : There is no reliable water source on the ascent to the Fenêtre d’Arpette, so carry enough from Champex.

Col de Balme, Lac Blanc & the final section

The final section towards Col de Balme, Lac Blanc and Chamonix remains snow-free and in excellent summer condition.

The big consideration here is again the heat. The exposed trails can feel surprisingly hot in the afternoon, particularly after several days of hiking.

Start early, carry plenty of water and enjoy the views before the afternoon haze builds. If you have the energy, bag Croix de Fer and / or Col de Possettes before heading down to Le Tour!

On the 21st August we had the first downpour of rain all month! It rained none-stop from about 10 AM. Well done to Cecilia and her group, who hiked up and over Col de Balme!

What’s on in September? More than just TMB conditions!

September is a lovely time to be in the Mont Blanc region. The summer crowds begin to thin out, the evenings feel cooler and the mountains start to take on their autumn colours. There are still plenty of events happening, particularly around Champex-Lac and Courmayeur.

European Heritage Days, 13 September, Champex-Lac
If you’re passing through Champex-Lac in September, look out for the European Heritage Days on 13 September. This year’s programme includes a guided visit exploring endangered alpine plants, a lovely opportunity to learn more about the flora you’ll have been walking through on the TMB.

Lo Matsòn, 5 September, Courmayeur
Courmayeur’s Lo Matsòn celebrates the best of local food and producers, with a market showcasing products from the Aosta Valley. It’s a great way to discover some of the flavours of the mountains after a few days on the trail.

Harvest season in Valais
September is also harvest time across the Swiss side of the TMB. The “At the heart of the harvest” celebrations run from 12–20 September in the Coteaux du Soleil, while the Semaine du Goût Valais runs from 17–27 September around Liddes and Vichères. If you have time to linger after your hike, and if you have a car or other means of transport, this is a wonderful time to enjoy the food and wine of the Valais.

A little tip: September is quieter than August, but don’t assume that everything will still be open. Some mountain refuges, lifts and restaurants begin closing. Check opening dates and book ahead, particularly if you’re hiking later in the month.