Framing the Question
When people start to plan their TMB, one of their first questions is inevitably on the best time to hike the Tour du Mont Blanc.
The answer, like so many things in life, is it depends.
Let me start out by saying that as a tour operator, we run self-guided tours from the end of June to the middle of September. So that already narrows the range of answers quite a bit. Within that time period, there is not one best time that will fit everyone. The best time comes down to the individual and what their priorities are.
LET YOUR PRIORITIES GUIDE YOU
Some people's top priority is to have solitude on the hike. Others, perhaps those traveling alone, prefer to complete the tour when a lot of people are on the trail, to maximize the chance for camaraderie. Still others, place a high importance on seeing alpine flowers (hint: early in the season is best for that). And some want to make sure they don't encounter any snow on the trail (hint: August is best for that).
In short, there are many factors to consider when choosing your Tour du Mont Blanc dates. I've listed a few below.
- trail conditions
- blooming of alpine flowers
- other events taking place on the tour - from August 28 to September 2nd the trail is full of spectators watching the Ultra TMB
- number of hikers on the trail
- opening and closing of huts - Huts will open around June 15 and start to close September 15
- the running of public transport
- and most importantly, your own availability.
Let's take a look at a few of these considerations in more detail.
(Photo: A Trail Runner near Le Brevent on the TMB)
TRAIL CONDITIONS of the Tour du MOnt Blanc
The consideration of trail conditions is important when choosing your start date. If you leave too early, there can be Neve, or snow patches, throughout the trail. Snow can make hiking the TMB difficult in a number of ways. When snow is hard and your boots cannot gain traction, there is a risk for slipping, which is especially dangerous along steep pitches. In some cases, crampons and other alpine equipment may be necessary during the early parts of the season. Furthermore, the snow can obscure trail markings and can make route finding more difficult.
It’s hard to predict when snow will be clear enough from the trail that it won't throw a wrench in your hiking plans. The amount of snowfall during the winter and the temperatures of spring affect the amount of snow left on the trail during the summer. Each winter and each spring is slightly different. To add further perspective, here is a bit of history about the conditions early in the year from the last few seasons.
- I hiked the TMB this season (2017) from June 15th to the 25th. There was some snow in parts, however crampons were not necessary at all and the snow was generally not a concern.
- In 2016, people were using crampons in late June – not all the time, however on the main passes and at higher elevation - and there was quite a bit of snow, even into mid-July.
- In 2013, a particularly heavy winter and cool temperatures lead to bad trail conditions until the end of June and into July. Hikers needed to skip some passes (example the Grand Col Ferret) and sections (near Col de la Croix du Bonhomme) because of the steepness of the trail and the difficulty in route finding due to the snow cover.
FYI - as a tour operator, the earliest start date we accept reservations for is late June. The latest start date for the complete tour is September 5th.
WEATHER on The TMB
The weather is another consideration when planning your TMB. July and August have the highest temperatures, while June and September are more mild. In June, the average high in Chamonix is 68 F and the average low is 48 F. The average high temperature during both July and August in Chamonix is 72 Fahrenheit, with an average low of 52 F. The average high in September is 66 F and the average low is 48 F.
The TMB ranges in elevation from around 3,500 ft in Chamonix to 8,323 ft on the Grand Col Ferret. Some alternative routes, like the Fentre de Aprette and Col des Fours, reach up to 8,745 ft. With a wide range of elevation, the temperatures can vary greatly. Below is a breakdown of the temperatures by month for four different elevations.
The graphs display temperatures from Chamonix, France (3,477 ft), Col de la Forclaz, Switzerland (5,009 ft), Rifugio Bonatti, Italy (6,643 ft) and Le Brevent, France (8,280 ft). It provides a good cross section of both locations and elevations of the tour. The temperatures are taken from a 30 year average from Meteo Blue. Here is what they say about interpreting the data:
- The "mean daily maximum" (my graphs, the "Average High") shows the maximum temperature of an average day for every month... Likewise, "mean daily minimum" (my graphs, the "Average Low ") shows the average minimum temperature. Hot days (my graphs, the "Average Hottest Day") and cold nights (Excluded from my graphs) show the average of the hottest day and coldest night of each month of the last 30 years. For vacation planning, you can expect the mean temperatures, and be prepared for hotter and colder days.
I left out the cold nights from my graphs, as you won't normally be hiking at night.
Putting it all Together - A brief overview of each month:
- Late June – this is the earliest we take reservations as there can be snow and ice left on the trail. It’s hard to predict when the snow will be free from the trails. This year was great, and only a few spots of snow were remaining by the middle of June. The year before, there was considerable snow even into July. It’s very hard to tell. The temperature will be ok during this time for hiking, however you are more likely to catch a snow storm than in July or August (although, it will snow about once or twice a month even then). Late June does have less people on the trail and can make for a very relaxing tour. Still, if you are not comfortable with the idea of crampons in case of ice or snow, then I would avoid this time just in case.
- July – Early to mid-July is a good time as the tour hasn’t reach its maximum capacity yet. Wildflowers will be in full bloom and there should be fewer hikers on the trail than in August. Regarding trail conditions, I would say starting in the middle of July is a safe bet to avoid snow, however most years starting earlier is no problem. Still, be careful of the time around July 14th. This is Bastille Day in France, and many people either use it as a chance for a quick get-a-way, or a chance to start their longer vacation. Avoid the few days before and after.
- August – This is the busiest time of year for the TMB as most Europeans have vacation in August. Summer is in full swing and weather is perhaps the best of the season. All the public transport and lifts are running, so for those that may wish to have some cheat days, this is a prime time to be on the trail. Some wildflowers that start blooming later, like Edelweiss, Jasmine and Chickweed, may be on full display. The 15th of August is a bank holiday in France, so day trippers / weekend warriors can add to the amount of hikers on the trail during this time. Also, the Ultra Marathon runs the last weekend in August (2018 August 28th to September 2nd). If you are interested in seeing part of the marathon, you could end your tour around this time. The trails will be super full of runners and spectators however, so it's not a good time to hike the TMB.
- Early September – Early September can be one of the nicest periods on the TMB, as the weather is normally stable, and precipitation should be less than June - August. Furthermore, it’s not as hot in the valleys and there are less people on the trail. Still, there is a chance that you catch some snow storms, especially around the middle of September. Please note, not all the public transport is running during this time, so if you are counting on some cheat days with a bus or shuttle, it becomes harder to do that in September. Also, the latest most of the huts stay open is the 17th of September. A good time is between September 4th and September 16th.