Most cars come with all-season tires. Imagine using the same pair of shoes for jogging, hiking, tramping through snow, and ballet dancing, and you'll understand the problem inherent with all-season tires.
If you live where it snows, buy a set of proper snow tires (also known as winter tires) and use them in the winter. All-season tires are designed to handle all weather conditions, but they aren't optimized for any particular one. Snow tires are designed for one thing and one thing only: Keeping your car going where you point it when temperatures are low and the roads are covered in snow and ice. By using snow tires in the winter, you can opt for a "summer" tire better suited to your tastes -- be that a quieter, more comfortable ride, better handling, improved rain performance or longer tread-life.