MetService says winds gusting up to 120km/h will begin buffeting much of the South Island from Thursday evening.
Strong to severe gales are forecast for inland parts of Southland and Canterbury, and higher ground in Otago.
MetService spokesperson Daniel Corbett said the gales will peak between midnight and about 6am on Friday.
Mr Corbett says people should make sure loose items on their properties are secured, and anyone driving a high-sided vehicle should be extra careful.
