Explain California.
Los Angeles and a few other cities are somewhat of an exception to the general rule, I admit, and obviously the weather is one of many factors in determining where liberalism festers. Perhaps liberals just like to move to areas which are cold, as the cold weather helps facilitate their anger and bitterness.
Covering CA specifically: look at any weather map, and you’ll see that temperatures in CA dramatically increase as you head east; conservatism similarly increases. The most conservative big city in CA is Anaheim, the most liberal city is the frigid San Francisco. (Remember, CA also gave us Reagan; with the exception of Alaska and perhaps Michelle Bachmann, the best conservatives seem to come from warmer climates.)
Here’s a chart of liberal and conservative cities, notice the correlation: