Hear-hear on "there's more to life than money", but would still argue many of the things you list ("weather, local arts, music, culture") can be quantified to far larger extent than most bother.
Here's one attempt, as an appropriate illustration for the Bay Area: https://teleport.org/cities/san-francisco-bay-area/
(skip the top for startups, worst for housing and unfold the leisure, culture and tolerance categories, for example).
Median LA developer salaries on full time basis (https://teleport.org/cities/los-angeles/salaries/) seem to be 66k for web developer (for the lack of FE in taxonomy) and 78.7k for software engineers in general.
Without knowing your personal tax situation it is hard to deduct your net hourly income from this - so probably more useful to discuss and compare gross (pre-personal-tax) billing rates when trying to understand the market?
This question has come up so often in last few weeks that we gathered some reading and tooling to help pragmatic post-Brexit decision making, here: https://teleport.org/brexit
There is quite a lot of US visa related guesswork going on in this thread - please do seek expert advice. In my experience the application and compliance problems look much less scary when you talk to someone who does this every day. Lawyers are expensive, but try: http://teleborder.com (YC startup)
And on the global search for alternatives, should US not work out, here's some overview data of 110 most startup-friendly cities in the world: http://my.teleport.org/ -- and a mobile app for searching among them: http://teleport.org/mobile
(visa data layers coming soon, too, but dozens of other cost & quality of life criteria already there)
we've been on Fleep with our distributed team of a dozen people for a year now and very happy with it. the quickest way to think about them is that if Slack is a modern take of IRC, then Fleep makes Skype's model of persistent p2p chats work (fast, mobile, syncing well, file storage, some clever UI improvements, web access).
* https://www.expatistan.com/cost-of-living/san-francisco
* https://teleport.org/cities/san-francisco-bay-area/
* https://nomadlist.com/san-francisco-ca-united-states/scores