I used to live in Santa Monica many years, and you can't predict some unusual heat wave, but in general, winter is winter. We even wore wool coats at times in January (not real heavy, but still, it could be in the low 40s in the morning, or 30s overnight).

I think you have to leave the US and get closer to the equator. Go to Cancun or something like that.

Farmers Almanac predicts weather will be .5 degrees colder in Florida for the month of January 2010.

http://www.almanac.com/weather/longrange/FL/Orlando

Jan. '08 and '09, I was in Naples, FL for most of the month and the temps were in the mid to high '70's, with a few days hitting 80 as I recall...

Mexico. You cannot count on Florida--been there done that. But you can always take a chance. Further south the better.