Cold wave and Cold spell

Cold wave noun - A weather condition marked by low temperatures.

Cold spell and cold wave are semantically related in very cold weather topic. In some cases you can use "Cold spell" instead a noun phrase "Cold wave", when it comes to topics like advancing front of colder air.

Cold spell noun - A spell of cold weather.

Cold wave and cold spell are semantically related in very cold weather topic. You can use "Cold wave" instead a noun phrase "Cold spell", if it concerns topics such as advancing front of colder air.