Another sure sign of fall is when the cruise ships start coming back in town. San Diego is mostly a gateway to Mexico, and most cruise lines don't frequent the Mexican Riviera in the summer - too hot!
The Mr and I have taken two cruises together, both on Holland America's "Dam" ships (so-called because all of their ships' names end in 'dam' - Zuiderdam, Ryndam...), so we are always happy to see the Dam ships back in town.
We get a lot of different ships at the beginning of the "Mexican Riviera" season, and then again, in the spring, at the beginning of the "Alaska" season. Today we have the Volendam, coming down from Alaska and off on her way Australia and the South Pacific.
I work on the harbor and walk by the ships every day. Makes for some nice daydreams, thinking of the places they'll go!