Not only that, but in my experience it seems like the short-distance west coast flights (LAX, SAN, PDX, etc) are almost always the first to get delayed when the fog rolls in. My guess is since the planes are smaller and have a fair number of commuters there are fewer onward connections that get missed from these flights, so it's less costly to delay those first.

I used to fly Delta a good bit, which required a lot of connecting through LAX, and it seemed LAX-SFO in the summer was rarely if ever on time.