A year in Chamonix is a round of glorious seasons – fresh springs, warm summers, golden autumns and white winters – with a six month skiing season.
Temperatures range from around 25-30 °C on warm summer days to well below freezing in midwinter, with snaps of -25°C not unknown.
For some reason, most temperature graphs for Chamonix take their temperatures from the station on top of the Aiguille Du Midi where it rarely drops below freezing, causing a lot of confusion.
Here’s one that is more accurate. Even this one is a little confusing. I think the low average minimum temperature is due to the wide fluctuation throughout the day, and must be taken from very early mornings. 10°C would be most unusual during the day in July! The maximum temps look about right to me.
Like all mountains, Mont Blanc is a weathermaker, and conditions can change very quickly, so these are just general guidelines. Here’s a rundown of what to expect…
December is when winter really moves into the valley- sometimes there can be thick snow all over the valley floor by early December, other years the snow level can be higher, but there’s normally snow in the town for Christmas.
January is usually the biggest snow month. It’s normally very cold – temperatures rarely get much above freezing, so the conditions are great with the cold keeping the powder light. This is my favourite time of year for skiing and snowboarding – after New Year, the slopes are very quiet. The ice climbing season is in full swing and the cross-country ski tracks open. January’s early sunset times mean spectacular views from the slopes!
February is usually a few degrees warmer, but still very cold, with increasing snow depths – in good years, we’ve had a metre and a half in the garden at this time. It’s a busy time with school half terms, so make sure you book accommodation, travel, equipment hire, guides etc well in advance. It’s worth checking the dates of the UK and Paris (French Zone B) half terms if you have flexibility in your dates.
March brings steadily warmer weather, and still great snow, with more sun and clear views. With the school holidays over, this is the time for groups of friends to come, so the bars are generally very lively at this time! Parties like the Black Weekend and the Winter Sessions keep the bars and clubs going till the small hours. On a more wholesome note, ski touring season begins in earnest with the longer days, better weather and well filled glaciers. A good month to come if you want to do some off-piste, as the better snow depths (around 2.5m on the higher slopes, occasionally reaching 4m at Grands Montets) mean that more of the classic routes are likely to be in good condition.
April – spring skiing, and Easter holidays bring everyone out to enjoy the sun and snow. This is often a very beautiful time in the valley, with early blossom starting to appear on the trees as spring begins, and still great conditions on the slopes, since most are above 2000m. It’s a more relaxing time of year, with barbecues and sunbathing. Don’t forget the sunblock! Also an excellent time for ski touring.
May is when the lifts finally close – look out for the Freeride Days closing party, usually early in the month. It can still be a good time to do high altitude off piste like the Vallee Blanche and some ski touring. The lower hikes start to be accessible. Ski or board in the morning, then hike, climb, golf or mountain bike in the afternoons! The Aiguille du Midi remains open, and possibly Montenvers.
June is sunny and fresh, with flowers everywhere. It’s perfect hiking and climbing season, and the best time of year for watersports like rafting, hydrospeeding and canyoning. The mountains are quiet and it’s a lovely time for tranquil walking, though many high walks will still be inaccessible due to snow. Around the middle of June, the lifts restart. A great month for mountain biking as it’s not too hot and all the trails are open (In July and August, some of them become pedestrian only)
July brings beautiful clear days – this is sunniest month in Chamonix. Walk through shady woods or take the cablecars and mountain railways for spectacular scenery. It’s lively, but not as busy as August, and an excellent time to visit. All lifts are open for mountain biking on the bike-specific downhill and cross-country trails in July and August. Late June and early July are also among the best times to see the mountain flowers.
August is the busiest time of year for Chamonix – busier than even New Year or half term week. It’s usually hot and sunny (around 25°C in the valley on average) though there are sometimes dramatic summer storms in the late afternoons, which freshen everything. A wonderful time to take shady hikes to beautiful viewpoints, and enjoy the lively, cosmopolitan atmosphere in the town. The trails are still all open for mountain biking.
It can be good to plan your activities to avoid the heat of the afternoon. My perfect August day is to hike, cycle or climb in the fresh early morning air, cool off with a swim, then come back to enjoy a tranquil and lazy afternoon between the hammock and the hot tub at the chalet, before an evening barbecue.
September is a great time to visit – it’s actually the driest month, with lovely temperatures and a brilliant time for mountain biking and climbing. The lifts close mid-September, apart from the Midi and Montenvers, but the first two weeks, with full lift access and a more relaxed atmosphere in town after the feverish excitement of the UTMB at the end of August, are one of the best times to visit. You don’t get so many flowers as earlier in summer, but the autumn colours are sometimes just beginning.
October is quiet and autumnal – there are still some beautiful days and wonderful light in the valley as the larches turn golden. The lifts often open for weekends throughout October and November. The high walks become an amazing sight as the larches turn gold and carpet the ground with their wonderful colours.
November has a feeling of anticipation and misty days as winter begins to make itself felt – though even now you can get some beautiful autumn weather.