Wow, TechWriter... this is downright magnificent. And I thought I was anal-retentive! :D
Unlike you, I was able to eliminate the entire rest of the country except the Left Coast, because humidity makes me INSANE. Luckily, I do have lots of personal experience with most of the parts of Calif, which sped things up a bit.
"John & Angela" was right about parts of Mexico, too, from everything I've read: Lake Chapala is an ex-pat haven, in large part because of the wonderful year-round weather.
My plans are shaping up to be: Washington near the Canadian border from June to August (though June in Washington can start out cold), then working my way slowly down the coast until I get to near the Mexican border, for the winter months.
Fall in Calif is unpredictable; I wouldn't want to risk Sacramento and south of there until mid-October. It will generally be cooler than 75 degrees after that, but I'll take "cooler" over "85 degrees" any day. :D
