The top of the country has been warned of heavy rain and thunderstorms lasting until tomorrow afternoon.
MetService has issued a severe weather watch for Northland and Auckland as an active trough was expected to bring periods of heavy rain and thunderstorms.
It said rain was likely to at a rate of 25mm per hour, which could result in flooding, especially in urban areas.
Driving conditions could also be very hazardous, Met Service said.
WeatherWatch.co.nz analyst Philip Duncan said there was also a low risk of flash flooding.