In official terms, all-season tyres are classed as winter tyres. When making a purchase, ensure that the tyres are labelled with the snowflake symbol (also known as the alpine or 3PMSF symbol) or the M+S symbol (manufacture before 2018, valid until 2024).
Manufacturer names such as “All weather” or “All season”, as well as special weather symbols (a snowflake, leaf, sun and raindrop) on the tyre sidewall, indicate that the tyres are suitable for all seasons.