Without talking about specific locations, the key concepts are elevation and latitude. For every 1,000 feet in elevation the mean temperature drops 3.5 degrees F. In the northern hemisphere, every 15 degrees of latitude north means a drop of 5 degrees F. Of course, there are exceptions to this. Snowbirds and full-timers often follow one of two rules: 1) I-10 or south in the winter/as far north as you can get in the summer; or 2) as the Harry Nilsson song said, "I'm goin' where the weather suits my clothes."
Rob