MetService says a front will move up the country on Saturday.
A wet and windy Saturday is forecast for some, and more settled but cooler weather is expected on Sunday.
Meteorologist John Law said there would be unsettled weather this weekend as a front moved up the country on Saturday bringing some heavy rainfall towards the west coast and stronger winds.
"By the end of the day that wet weather and those stronger winds transfers towards the North Island as well."
The MetService says showers turning to rain are forecast for the north and west of the North Island on Saturday, but they will ease to isolated showers on Sunday morning.
In the South Island there will be rain in the south and the west which may be heavy on Saturday, but it is expected to clear in southern Westland, Otago and Canterbury later in the day.
More showers are expected in the south and west of the South Island on Sunday, but it is expected to be mainly fine elsewhere.
Beginning early on Saturday, vigorous westerly to northwesterly winds are forecast to sweep over the South Island and lower North Island, and there are several strong wind watches and heavy rain watches in place, including for Dunedin and much of the South. The winds are expected to ease on Sunday.
Law said the front was expected to move through fairly quickly and it was expected to clear by Sunday with more settled weather but cooler temperatures.
There would still likely be showers in the southern part of the South Island on Sunday, he said.
Weather watches
Strong Wind Watches
Dunedin, coastal Southland and Clutha, including Stewart Island - 28hrs from 2am Saturday to 6am Sunday.
Fiordland, inland Southland and Clutha, also Queenstown Lakes and Central Otago - 8hrs from 2am - 10am Saturday.
North Otago, the Canterbury Plains, also Christchurch and Banks Peninsula - 12hrs from 5am - 5pm Saturday.
Heavy Rain Watch
Fiordland - 14hrs from 11pm Friday to 1pm Saturday.
Road Snowfall Warnings
Crown Range Road - 8hrs from 5pm Saturday to 1am Sunday.
Milford Road (SH94) - 12hrs from 2pm Saturday to 2am Sunday.
- additional reporting ODT Online