This is from a couple of winter trips to Yosemite - one at winter solstice 2007, the other over Christmas 2013. The 2013 set includes a visit to Sequoia NP. The 2013 trip was with beautiful weather - sunny and 30F at night, 55-60F during the days - but was disappointing for that very reason... I wanted snow and between the drought and global warming, there were only tiny amounts of snow in shadowed areas. It's also the least amount of water I've ever seen at Yosemite which appears to have become a 'seasonal' waterfall wonderland. We had fun anyway but I'll have to get back one Springtime after a snowy Winter.