If you have studded tires I would probably wait a bit longer but it depends on where you live. Legally you are OK anytime after October 1 but studded tires + bare pavement = poor traction, so if you realistically don't expect to be driving in snow for another month I would stick with your all seasons. If you are talking about studless winter tires, yeah go ahead. They do well with cooler weather, rule of thumb is to switch them when averages are 50 °F or below.