Most of the east coast of the country is forecast to be hit by heavy rain on Thursday, including already drenched Hawke's Bay.
It comes after the region suffered immense devastation following Cyclone Gabrielle.
A frontal system over the South Island is moving northwards to reach the central North Island on Thursday, bringing rain with heavy falls.
MetService has issued a heavy rain watch from Otago to Hawke's Bay, warning the watch could be upgraded.
"Hawke's Bay, in particular, could see an extended period of rainfall, and this Watch is likely to be upgraded to a Warning," MetService said.
The weather forecasting agency has placed Hawke's Bay under a heavy rain watch from noon Thursday until noon Saturday.
The region was one of the hardest hit by Cyclone Gabrielle last week which brought severe flooding to the Hawke's Bay.
A heavy rain watch has also been issued for Wairarapa from 6am Thursday until 6am Friday.
Meanwhile, in the South Island, Canterbury, the ranges of Westland south of Otira and Otago are under a heavy rain watch until later on Wednesday.
