Who knows, dense fog could be an artifact of the abnormally wet 20th century that California has seen, looking back 2000 years the typical state for California is very dry. Back 1200 years there were a few megadroughts that lasted centuries, here is an article that shows history of drought/rain in California, (on the infographic showing wet and dry periods) notice the huge peaks in the 20th century, and the steep drop in the 21st century.
I assume this consistent fog is an function of higher latitudes with dry hot inlands and cool oceans. Especially in the desert, fog will form near the coast.
As SF Bay adds a lot of coast line, meaning more cool ocean closer to more hot land than most coastal cities, I'd imagine that has a large effect on why fog forms.
If ocean temps rise faster than average land temps, the average difference between them will shrink, perhaps bringing on average less fog?
yes, but also look at the age of the trees in the coastal forest (or the age of the trees which didn't get cut down by us). Suggests that they might be a different "micro" climate; also note the earlier comments that they create fog.
https://www.nytimes.com/2015/04/14/science/californias-histo...