the calm before the storm
US /ðə kɑːm bɪˈfɔːr ðə stɔːrm/
UK /ðə kɑːm bɪˈfɔːr ðə stɔːrm/

1.
暴风雨前的平静
a period of unusual quiet or inactivity before a period of great activity, excitement, or trouble
:
•
Everyone was quiet, but I knew it was just the calm before the storm.
所有人都很安静,但我知道那只是暴风雨前的平静。
•
The quiet morning was the calm before the storm of the busy workday.
宁静的早晨是繁忙工作日暴风雨前的平静。