Jīngzhé, 惊蛰, is the 3rd of the 24 solar terms (節氣) in the traditional Chinese calendars.
[1][2] The word 驚蟄 means the awakening of hibernating insects.
驚 is to startle and 蟄 means hibernating insects.
Traditional Chinese folklore says that during Jingzhe, thunderstorms will wake up the hibernating insects, which implies that the weather is getting warmer.
[3] Each solar term can be divided into 3 pentads (候).