People look down on stuff like geography and meteorology, and not only because they're standing on one and being soaked by the other. They don't look quite like real science. But geography is only physics slowed down and with a few trees stuck on it, and is full of excitingly fashionable chaos and complexity. And summer isn't a time. It's a place as well.
Summer is a moving creature and likes to go south for the winter.
Even on the Discworld, with its tiny orbiting sun tilting over the turning world, the seasons moved. In Ankh-Morpork, greatest of its cities, spring was nudged aside by summer, and summer was prodded in the back by autumn. Geographically speaking, there was not a lot of difference within the city itself, although in later spring the scum on the river was often a nice emerald green. The mist of spring became the fog of autumn, which mixed with fumes and smoke from the magical quarter and the workshops of the alchemists until it seemed to have a thick, choking fife of its own. And time moved on.