天气变得凉快了 Weather gets cool ; The weather became cooler ; The weather became cool the ; The weather is cool

天气慢慢变凉了 Weather gradually cools the ; The weather slowly getting cooler

天气越来越凉了 The weather is getting cold ; It is getting cold

天转凉了 Day extension cool ; a cooler day ; Day cooler

天气凉了 the weather gets cold