The time to switch from all-season tires over to winter tires is when the temperature starts to stay below 45 degrees, or when there is consistently snow and ice on the road. Normally, all-season tires are the toughest and most useful tire, but in those conditions, winter tires get better.
They are made of a particular blend of rubber that works better in cold temperature. They also have a unique design in their treads that pushes out soft slush and other material, but grips harder on snow and ice than other kinds of tire. However, winter tires don't work…