Much of New Zealand will get a short reprieve from the wet weather on Wednesday evening before a second front reaches the South Island early on Thursday.
The West Coast and northern parts of the South Island, as well as Taranaki, Wellington and central parts of the North Island, have all experienced heavy rain throughout New Year's Day.
Taranaki bore the brunt of the bad weather in the afternoon, with thunderstorms and heavy rain. Buller, Westland, eastern Nelson and parts of the Marlborough Sounds also experienced heavy rain throughout the day.
Despite a chance of thunderstorms in North Otago and South Canterbury, there will be a general easing of conditions before another front brings strong winds and heavy rain on Thursday.
The MetService warns streams and rivers are likely to rise rapidly, with possible flash flooding.
Spokesperson Dan Corbett says conditions are looking very spring-like, with wet weather one day and fine conditions the next. That pattern set to continue until the second week of January, when a high arrives and things settle down.