I am trying to find weather conditions, and I think this Mount Washington Observatory may be somewhat higher altitude: https://www.mountwashington.org/experience-the-weather/mount-washington-weather.aspx
Temperature change with elevation: http://www.onthesnow.com/news/a/15157/ask-a-weatherman--how-does-elevation-affect-temperature-
Not seeing a lot of snow, where we are going, based on doing a search for “New Hampshire” on this site the says it has relatively live satellite photos (Landsat Live):
Found site linked from http://www.citylab.com/design/2015/03/roam-the-earth-in-real-time/388252/
This site says that the weather station is NHFN1: http://www.weatherforyou.com/reports/index.php?pands=franconia+notch+state+park%2Cnew+hampshire
On the following map, you can turn on “Terrain” by hovering over “Map”: https://mesonet.agron.iastate.edu/sites/site.php?station=NHFN1&network=NH_RWIS
There I see, that the first hut is about 1000 feet above the station, or 3.3 degrees F cooler.
I later learned that the following app, if you put in the longitude and latitude coordinates, gives you the weather forecast at that very location, including altitude. Pretty awesome. https://play.google.com/store/apps/details?id=com.nstudio.weatherhere.free
Mosquitoes won't be as bad as later in the summer, but I think they are out already in late May. They don't bite below 50 degrees, or so I read at one site.
Black Flies we should worry about, according to Whiteblaze and Farmers Almanac. I'm going to see if I have a head net, just in case.
I'll be using clothes I've treated with permethrin.
Post backpack report (May 28-29-30): Nothing bit us. Didn't see any mosquitoes or flies!