It is important to maintain your tires inflated to their recommended tire pressure levels throughout the year to ensure comfortable and safe ride. That is especially true during winter, when temperatures drop, and so does your tire pressure.
It is simple physics - when the temperature drops, air inside your tires contracts, air molecules get closer together reducing the volume of air inside the tire, which causes tire to lose pressure.
That is why you have to check your tires in the winter often and compensate for the loss of air pressure due to lower temperatures by inflating your tires to their recommended tire pressure levels. General rule is for every 10 degrees Fahrenheit tire loses about 1 psi in tire pressure. So if you park your car in garage, inflate your tires a few psi higher than your recommended tire pressure so that when you drive outside where temperature is 20 degrees Fahrenheit colder, your actual tire pressure is at recommended level.
Make sure your tires are inflated properly to enjoy safe driving on winter roads. Check your winter tire pressure regularly and keep them inflated at recommended tire pressure levels.