MetService has issued a warning of heavy rain for much of the country over the next three days.
Affected areas include Northland, the Coromandel Peninsula, Nelson, Marlborough as well as the Canterbury High Country and foothills, where up to 150 millimetres of rain are forecast.
In the Nelson ranges, rainfall of 150 to 250mm of rain is expected.
The rain is expected to arrive on Sunday night and continue through Monday and Tuesday.
MetService warns rainfall of this intensity could cause rivers and streams to swell, with possible slips and flooding. It also warns driving conditions could be hazardous.
Duty forecaster Eric Brenstrum said a second front was due in the middle of the week. He said a second depression was likely to come down on New Zealand on Wednesday and it was likely to cause strong winds which could reach gale force in western areas of the North Island later in the week.