Oh, not to worry too much about it all. You could have a sense of humor about it. Or you could be just glad to find out this aspect of a place you were thinking of moving to. In either case, good to know before you get here, and all that.
So, another day goes by and no one steps up to the plate to hit you back some answers. I'll have a go at it then. Whatcom County grew by over 55% in the past 25 years ... faster than the average State growth rate ... About 60,000 new people up here in that time.. Lots of those new folks are from outside the State, including, quite significantly, California. You wouldn't hardly be alone ... and I'm not aware of any old-timer locals burning patchouli crosses on the lawns of California refugees, so you would likely be reasonably safe.
Here's the thing then: Whatcom County has Bellingham, accounting for over 1/3 of the population alone ... and Bellingham is a University town, which keeps it pretty youthful and fairly liberal-leaning. But the rest of the County is rural and farm / forestry towns ... and thems folks is not so liberal, eh? Lotsa newcomers in Bellingham ... fewer in the rural towns. (Exception of note: Birch Bay ... seaside resort-ish with fair amount of, and increasing like crazy, retirees.)
You asked specifically about Maple Falls ... uh, pretty, but you're not likely to enjoy that one ... as it has become a landing for quite a Slavic immigrant community -- and there's some troubles and criminal activity there between folks.
Then you asked about Ferndale ... which place I live in proximity to and am thus quite familiar with. Ferndale is an old farming community with a new identity-crisis in process. Linked to an I-5 freeway exchange (two, actually) Ferndale has become a favorite victim of developers of late -- eclipsed only by Birch Bay in that regard. Tacky, too. With nothing remarkable to recommend it. (At least Birch Bay has views and waterfront.)
To many native Washingtonians, the stereo-typical Californian is a vacuous creature with a fairly "scorched earth" approach to lifestyle. I have no idea whether you fit that profile, or whether you are wanting to flee California because you have become enlightened and disenchanted ... But, given that western Washington has roughly doubled its population since as recently as the 70's, the native Washingtonians are approaching "peak residential" status and should soon be on the way to extinction. Until that time, if you want Washington, you will likely not enjoy our true farm communities-- they are neither California-sophisticated nor like California farm communities, either.
However, you would likely find at least comfy anonymity, and downright California-leaning company in the Seattle area and certain rural communities, including: Port Townsend, Sequim, the southern half of Whidbey Island, LaConner, Olympia ... none of which are in Whatcom County. However, IN Bellingham, itself, you'd probably be happy, too.
Coming from California, Maple Falls is not likely a match (tsk tsk about its low real estate prices! there's a reason!). Ferndale, I doubt would appeal to you either. Lynden? hahahaha ... whole 'nother story for another time, if you want

(by the way, I lived in both the San Joaquin Valley and San Francisco, each briefly, many many many years ago -- and still love my several trips a year to camp all around that state -- but wouldn't live there if I had Bernie Madoff's hidden money)
If you like fanciful, quaint, rural ... like say: Fort Bragg or Arcata on your Calif. north coast ... if that's why you are attracted to NW Washington ... have a good look at south Whidbey Island. Really. And plenty California license plates being turned in there for Washington ones.
Oh, and, um, you really know about the weather up here compared to California? That's what drives LOTS of Californians back south. Really.
Good luck. More info if you want since no one else is chiming in
