It's quite a cold snap.

天气真冷。

There was a cold snap after Christmas.

圣诞节后出现一段寒冷天气。

This is a cold snap.

这是倒春寒。

We are having a cold snap.

我们遭遇了寒流。

Cold snap heading from north, west China.

寒流袭击中国北部和西部地区。