I honestly forget. But we usually go on vacation end of August/early September, because it is cheaper (all the families are going back to work and school by then). I may be mixing up my glaciers but this one was quite a hike to get to. It does get cold that time of year.
The USA also has nice mountains and some glaciers to visit, too. In the Grand Teton National Park, Wyoming (I recommend), there is a glacier or 2 there, too. A few other American and Canadian glaciers I have visited, but their names escape me for now.