表达 “a cold snap” 通常被用来描述 “温暖天气后出现的一段短暂的寒冷天气”。这种天气可能来得很突然。与 “a cold snap” 同义的另一个表达是 “a cold spell”。

• There was a cold snap at the start of the year.
  今年年初有一股寒流。
• The weather had been perfect for growing food, but the sudden cold snap threatened the crops.
  当时的天气本来非常适合种植粮食，但突如其来的寒流却危害到了庄稼。
• The weather forecaster said that a cold snap is heading our way, so we should probably postpone our holiday.
  天气预报员说有一股寒流正向我们袭来，所以我们或许应该推迟度假安排。