China's official 'heating line' runs roughly along the Qinling-Huai River (
秦岭-
淮河) — north of it, cities have municipal central heating (
集中供热) running roughly Nov 15 to Mar 15; south of it, residents rely on AC and space heaters even when it gets close to freezing. Whether your city has
供热 is itself a north-south cultural marker.