Wet weather in the top of the North Island is setting in for at least another day, and downpours are heading for the top and west of the South Island.
The rain is expected to continue in the north until early Monday, with bouts of heavy rain in some places from tomorrow morning.
MetService said Auckland, Waikato, Waitomo, Taumarunui, northern Taranaki, western Taupo, and Taihape including Tongariro National Park would get a soaking from tomorrow afternoon to early Monday.
Heavy rain is forecast for Horowhenua, Kapiti Coast, the Tararua range and Wellington from tomorrow afternoon until early Monday morning.
But the worst of the heavy falls in Northland would be over by midday today.
A complex low pressure system, with a series of warm fronts, is bringing the rain to both North and South islands.
Meterologist April Clarke said some parts of the country might get thunderstorms.
"With that ... front that's starting to sink over western parts of the North Island and upper parts of the South Island on Sunday afternoon, there could be thunderstorms as well as heavy rain."
The forecaster has issued a severe weather warning for Mt Taranaki, Nelson, western Marlborough, Buller and Westland during Sunday and early Monday. The ranges of northwest Nelson could have 130-180mm of rain on Sunday.
MetService advises people to to keep up to date with the forecasts and warnings in case other areas are added.
The the rain wasn't related to Cyclone Gita which has lashed Samoa with torrential rain and damaging winds as it strengthens to a category 2 system, but rather a slow-moving subtropical rain band, the forecaster said.