It's a cold snap.

Meaning

A short period of unusually cold weather.

Examples

• John: Brrr! It's freezing outside.
• Alice: Tell me about it. <b>It's a cold snap</b>, isn't it?
• John: I wish I'd brought a warmer coat. This <b>it's a cold snap</b> is brutal!
• Alice: Me too! Let's go inside.