Cold weather and Weather condition

Cold weather noun - A period of unusually cold weather.

Weather condition and cold weather are semantically related. In some cases you can use "Weather condition" instead a noun phrase "Cold weather".

Weather condition noun - The atmospheric conditions that comprise the state of the atmosphere in terms of temperature and wind and clouds and precipitation.

Cold weather and weather condition are semantically related. Sometimes you can replace phrase "Cold weather" with "Weather condition", this phrases are similar.