Strong winds and heavy rain are being forecast for this weekend with warnings this could lead to power cuts.
Severe northwest gales are predicted for Southland, Otago, Canterbury and the lower North Island and heavy rain over large parts of the country.
The temperature is predicted to drop after a relatively mild winter week.
MetService meteorologist John Law said rivers could rise rapidly and there was possibility of slips and surface flooding on roads so motorists should exercise caution.
Fine weather is expected to return in the South Island by Sunday and further north by Monday, he said.