Well, I would have to go with snow. Being Canadian and having lived in areas right across the country, I am well accustomed to extremes in cold weather. I would have a better chance of surviving in those conditions then in say, a desert or very hot, dry climate where I have very little experience. It really depends on the resources available.
My first 2 concerns would be water and shelter. In the snow I can create shelter by simply digging and packing the snow. Not so much in a desert. Same thing for water - assuming I had a means of making fire, snow and ice can be melted down and drank. If I cannot make fire, then I can at least melt the snow and ice in my hands and get some moisture into me.
We have some areas here where it can get very hot and dry during the summer, but there is almost always clumps of trees or bush you can use to create shelter. Plunking me into the middle of the Arizona desert would be a very good test of my abilities to survive.
Hope it never happens :tinysmile_fatgrin_t.