Geonet says the 5.2 magnitude quake struck about 20 kilometres west of Porangahau, in southern Hawke's Bay, at 3.18am, at a depth of 10 kilometres.
A number of aftershocks have been reported.
Newstalk ZB listener Lynn says woke up to "strong shaking" in central Hawke's Bay.
She says she's lived in Hawke's Bay all her life and has experienced many big earthquakes, and she'd describe this one as very shaky, and rattling everything in the house.