According to road traffic rules, winter tires are mandatory from November 10 - until March 31. Driving with studded tires is allowed from November 1 - until April 10 (i.e. from April 10 to October 31, it is prohibited to operate vehicles with studded tires). It is allowed to operate a vehicle with summer tires from April 1 - until November 9. It is important to take into account not only the established requirements of road traffic rules, but also real driving conditions. For example, in autumn (end of October beginning of November), especially in the mornings and evenings, we can get below 5°C or negative temperatures. In such weather conditions the grip of summer tires to the road surface is reduced and winter tires whose compound and technology are adapted to temperatures below 7°C, provide significantly greater safety. You must know - the minimum allowed tread depth of winter tires is 3 mm the minimum allowed tread depth of summer tires is 1.6 mm, but many tire manufacturers recommend changing tires when the tread depth of winter tires is 4-5 mm and of summer tires 2-3 mm. because the smaller the tire tread depth the worse the tire grip is. Finally, the time to change tires depends not only on weather conditions or tread depth - if the tires are damaged or unevenly worn it is also time to change them with new ones.