A heavy rain warning is in force for the Bay of Plenty, with MetService warning that it could be "extreme".
Downpours and significant flooding are possible for Bay of Plenty and Gisborne from midnight tonight until midnight tomorrow.
It warned people to expect 150 to 230mm of rain, though some areas may see more, said MetService meteorologist Lewis Ferris.
Streams and rivers may rise rapidly and flooding and slips were also possible, it said.
A "persistent" large band of rain was likely to sit over the Bay of Plenty but the intensity may be less than Auckland's downpour yesterday, he said.