There are many excellent hiking trails in the Chamonix region ranging in difficulty from very easy to somewhat strenuous. Summer is an ideal time for viewing wildflowers with numerous varieties throughout the summer, depending on elevation.
A few of the trails that I hiked or were recommended to me are listed below:
Glacier de Bossons is well worth the trip from Chamonix for those in reasonable shape. The entire round trip hike takes about 3 to 3.5 hours. This glacier almost reaches the valley floor and is easily seen from town. It is the lowest of all the alpine glaciers in the French Alps. From Chamonix walk towards this glacier. Hikers will soon reach the main road and continue on towards the glacier. The road is well signed pointing hikers in the right direction.
Soon the trail/path will pass a campground and will veer away from the road and will turn to dirt. This will pass near the road, but will not actually cross the road until you reach the Mount Blanc tunnel. Here you will cross the road after climbing up some steep stairs. Continue towards the glacier which you should still be able to see provided the day is somewhat clear. The trail begins to steepen at which point, hikers are still 1/2 hour away from the glacier over look. Coming down this portion of the trail, however, usually is much quicker. It took me only about 10 minutes to descend from the glacier overlook to the Mount Blanc Tunnel.
An image of a skull and cross bones are located the end of the trail. This glacier is extremely dangerous and no one is allowed to venture onto it. Take a few minutes at the glacier overlook and watch and listen carefully. Most likely you will see large chunks of ice and rocks crashing down. Some of these can be quite large and will make a lot of noise. Presently the glacier still extends below the lookout. However, at the current rate of retreat it will not be long before the glacier has retreated past the field of view from the lookout. If this happens the lookout may have to be moved higher up.
The western side of the valley is a great place to hike especially at dusk. From this side you have tremendous views of Mount Blanc and the surrounding mountains. There aren’t any specific trails on the valley floor that I recommend. I had a nice time just walking around the neighborhoods and rustic hotels.
Grand Balcon Sud trail is for the most part quite flat and runs along the western side of valley at about 6500 feet. Hikers can reach this trail from behind Le Brevent tramway. The hike up to this trail is about 3000 feet vertical so you may want to consider taking a tramway. Two tramways will whisk you up to the Grank Balcon Sud trail: Planpraz for a price of about 15 Euros, or the La Flegere for a price of about 16 Euros.
Lac Blanc at 7708 feet in elevation is a spectacular lake. Chances are you will see photographs of this lake in some of the Chamonix stores. It is a turquoise lake with excellent views of Mount Blanc. You can access trails from the top of the Les Praz L’Index tramway or the La Flegere tramway.