return of cold weather in spring; cold snap after warm days
Refers to a temporary return to winter-like cold during early spring, after a period of warmer weather. Often used in weather forecasts and seasonal conversation.
It was warm last week, but this week we had a return of cold weather and it snowed again.
寒の戻りに備えて、まだコートをしまわないほうがいい。
You shouldn't put away your coat yet, in case of a cold snap.