Yes, as already posted, the OP is far too early to buy airfare for Dec 2015, since these won't be released until late January- February 2015. Good luck finding a fare sale for a December flight!
You are mistaken if you think booking flights with connections in warmer weather airports is going to keep you from having weather related delays. Bad weather in one area of the country can affect flights all over the US. In fact, Atlanta has plenty of weather related delays:
http://www.ibtimes.com/winter-storm...rts-most-often-closed-due-bad-weather-1484458
By the way, you failed to mention SFO, which I believe has more weather related delays due to fog than any other US airport.