Cracked cymbals...need help/advice?

I have some really nice Zildjian A custom cymbals and recently after just about a year or two (and I don't even play that often) both of them have cracked. For drummers that know a thing or two, these aren't cheap or poorly made cymbals. These are some of the best you can buy. So my question is this. Why are they breaking so easily with me only playing a few times a month. I play a lot of rock music and I do use them decently hard, but I do not believe they should be breaking like this. Any advice? Does temperature (I live in Massachusetts) like when it gets really cold affect them? Should I not use them in certain temps? My drum set is in a finished enclosed porch with windows but no heat. What do you think?Cracked cymbals...need help/advice?
I'm a guitar player... not a drummer, but I know from playing in bands, that should be at room temperature before playing. They can actually give off a different sound when they are cold, but more importantly, when they are cold they can become brittle and break pretty easily. You gotta find a way to warm them up. Also, playing to hard will break them as well... especially when they are a little cold.