Heavy rain has pelted central New Zealand overnight, with severe thunderstorms possibly on the way, while rain is impacting highways between Whangārei and Northland, and on the West Coast.

A yellow severe thunderstorm watch is in place for Bay of Plenty, Rotorua, Taupō, Gisborne, Hawke's Bay and Taihape, with forecasters warning the slow-moving weather system will likely bring up to 40mm an hour of rain, localised downpours, surface or flash flooding, and possibly hail.

Mid-morning Monday, MetService lifted a series of orange and yellow heavy rain alerts that were issued for large parts of the South Island, but said heavy rain could still fall on Nelson, Marlborough, Canterbury north of the Rakaia River and in the Chatham Islands.

Overnight, central New Zealand had a soaking, with Wellington recording 31mm of rain in the first five hours of Easter Monday and more heavy rain forecast for the day.

The MetService warnings and watches map on Easter Monday morning.Image: Supplied/ MetService

RNZ