More wet weather, thunderstorms on the way with New Zealand expected to be hit by 'unsettled conditions'

More wet weather is on the way for much of New Zealand in the coming days after parts of the country were hit by rain overnight.

Auckland received between 30 and 50mm of rain on Tuesday night - and could be in for more downpours  in the coming days.

"Round two arrives Thursday PM and into Friday, with heavier rain expected," MetService said on Twitter.

And it's also bad news for Northlanders where thunderstorms are possible on Thursday and Friday and a heavy rain watch is in place.

It won't be much better in Coromandel, which is also expecting periods of heavy rain on Friday. 

NIWA said the wet weather spanned from a "plume of moisture" extending southward from the Coral Sea.

"This is expected to bring a period of rain, some heavy, to many regions on Friday," the forecaster said.

"Unsettled conditions are then expected to stick around over the weekend."

MetService is also forecasting heavy rain in Bay of Plenty, Rotorua and the Gisborne ranges.

Taupō is also being told to expect heavy rain on Friday, while Masterton will receive showers along with gusty northwest winds.

Palmerston North will also be wet with occasional rain, while Wellington can expect heavy downpours with northerly gales.

It will be a similar story in the South Island with heavy rain watches in place for the Tasman District west of Motueka, Buller and Westland.

Meanwhile, Dunedin can expect rain and fresh northerly winds and Invercargill will see downpours with possible easterly gales. Blenheim will also be wet with periods of rain and northeasterly winds, and Christchurch will also get Friday morning downpours.

Timaru has been told to expect similar conditions to Christchurch while Queenstown will get rain that could become heavy.