We will be in Chamonix in mid to late June. We plan to do the Grand Balcon Sud hike and the hike along the Arve River to get there (hikes 2 and 5 from RS France 2007). It looks like the highest point we will get to will be Plan Praz at 2000 meters.
For the rest of our 3 week trip we will be in warmer places -- Paris, London, Tuscany and the Cinque Terre -- even Aosta, I expect, will be warmer than these hikes.
Do we need winter coats for the Chamonix hikes? Could we get by with bringing long underwear (how many layers?) and sweaters? We are a bit short on middle-weight jackets in our family and don't want to buy them for the trip. (Our family includes 3 teenage girls, in case that shapes anyone's clothing advice.)
My teenagers are just indulging me by going to someplace even a little bit cold after a Chicago winter of hour-long public transit commutes to high school, and are also not pleased with having to put more into their suitcases. Any help would be appreciated.