Key is water content which at this time of the year refers to ice. The more ice the longer it takes to melt. Some of the relatively lower elevation sites (+9,000 have over 50 inches of water. And you are absolutely correct. The temp and weather this spring will be critical factor. Last year my typical extrapolations didn't work quite right due to the cold and snowy spring. Right now I'm thinking that last weekend of june will be about the start of some fairly conservative backpacking opportunities and I'm scheduling my midsierra hiking beginning mid July and a high Sierra trip (up to 11,000) a couple of days later and about 10 days earlier than I would like but family obligations trump my backpacking schedule. I'm really looking forward to my September trip.
Hello you are absolutely correct about water content. At the Leavitt Lake site right now the water content is over 80 inches and the April average is just over 50 inches. That means the site is 160 PERCENT aboove normal. If we have a cold spring who knows when you will be able to get up in the high country. This year water content is similar to 82-83, 94-95, and 05-06. In all of those years I wasn't able to go to some of my favorite locations in the Sierra until mid- August. I think 94-95 was the worst thats when Mammoth Mountain had its longest season. It closed on August 13th 1995.