My first set of these and most of my second set were used in Upstate New York. In pretty much any weather conditions, they performed incredibly well. My case and point for their performance in NY is that I used to be able to make it from my house to my fire station(was a volunteer firefighter in NY) in even the worst of snow storms. I remember back when we had that huge ice storm in December a few years back, and it was like driving on a dry road even then.
Recently, I moved west, and drove my car all the way to California. It was late March, so I didn't see much weather on until about Wyoming where I experienced extremely fast crosswinds on I-80. These tires kept me glued to the road in that. When I got to Utah, there was some snow and slush, but these tires cut right through it. And when I got to the Sierra Nevadas, I was at 4/32s of tread left on my tires(just at the legal limit for not needing chains on I-80 in snow conditions), I traversed the mountains during the height of a snow storm and had absolutely no problems whatsoever with handling or braking in the Sierra Cement.
Now I'm here in one of California's hot valleys where it's blisteringly hot during the summer days and it rains buckets for periods during the winter. None of the weather conditions here have even put these to the test, even on the tires last legs(one's almost bald). I will be putting another set of these on my vehicle shortly. They've performed so well up until this point, I couldn't imagine buying a different set.