Originally Posted by JCL

The correct name should be winter tires, as in your post, not snow tires as in your title.

You should run the same type of tire on each wheel. In some jurisdictions it is illegal to run winter tires on only one axle. It is unsafe in any case.

Tires have certain handling characteristics with respect to grip. If tires with different compounds are run on each axle, you change the handling characteristics and can end up with too much understeer (plowing) or too much oversteer (rear end breaks loose).

You don't want to run winter tires above about 7 c (45 F) because they have a softer compound that is designed to stay soft in colder ambients (for sufficient grip) but which will wear very rapidly above the temperatures they were designed for.