Metservice forecast another burst of heavy rain on Saturday night and on Sunday in Westland, the upper South Island and about Mount Taranaki and the Tararua Range.
The forecaster said the rain would be preceded by north to northwesterly gales and would be particularly bad in the Buller and Nelson ranges and northwest parts of Marlborough.
MetService warned outdoor activities were likely to be hazardous as the severe weather hit, with slips and localised flooding possible.
An earlier heavy rain warning prompted police to warn trampers off mountainous areas in the upper South Island.
Nelson Senior Sergeant Stu Koefoed said high rainfall in a short period meant waterways would rise quickly and trampers could find themselves isolated.
Motorists were being asked to take care on State Highway 6 between Fox Glacier and Haast on Saturday due to surface flooding.