Heavy downpours are hitting Tai Rāwhiti, north of Gisborne City on Saturday, with the area under an orange heavy rain warning.
MetService forecasts revealed that 40 to 70mm of rain was expected, on top what had already fallen, until 5pm.
The largest amounts of rainfall were likely north of Tolaga Bay with peak rates of 10 to 15mm per hour, it said.
There was a minimal chance of the warning being upgraded to a red warning, MetService said.
A low pressure system swinging across the northeastern corner of the country was the culprit behind the wet weather, it said.
Meanwhile, MetService has also issued a strong wind watch for the Chatham Islands from 9pm on Saturday until 9am on Sunday.