MetService is warning of heavy rain and strong winds in parts of Westland and Fiordland from Saturday afternoon through to Monday morning.
The warning affects south Westland and northern Fiordland, where up to 120 millimetres of rain is forecast from Saturday evening.
Heavy rain and cold conditions are also forecast for eastern Otago and inland Southland from early Sunday morning which could cause streams and rivers to rise rapidly.
Severe south-east gales are also expected in Fiordland and southern Westland from late Sunday into Monday morning.
MetService also warns of severe north-west gales in Auckland and Northland later on Sunday which could cause damage and make driving hazardous.