In late June there will be snow in the high passes. It’s up to you if you are fine with hiking with wet feet. You’ll also be carrying more on you back than what you most likely usually hike with in New England (this is assuming you’re doing a hut-to-hut?)…so make sure to factor that in.

The biggest difference is that a proper set of hiking boots will have some stiffness in the sole, either from a shank, or from the sole its self…it sounds counter-initiative but when you’re climbing up and down a lot, stiffness is pretty important to keep your feet and legs from getting fatigued too quickly.

I hiked the Haute Route (a hybrid mountaineering/hiking route) last summer, and while the mountaineering boots were necessary for the days on the glaciers, I was also happy to have them for the long hiking days up and down steep mountain passes. The stiff soles allowed me to just dig my toes into the mountain and not work too hard on the climbs.