A strong wind warning is in place for the capital on Friday, while parts of the central and northern South Island are being drenched with heavy rain.

MetService said a front impacting parts of the South Island and the Tararua Range had hit on Friday and strong northwesterlies could reach a severe gale in eastern areas from Canterbury all the way up to Hawke's Bay.

A strong wind warning had been issued for Wellington and Wairarapa, excluding the Tararua District, from 4am on Friday through to 12pm.

Severe gales gusting up to 120 kph in exposed places were possible, the forecaster said. This could bring damage to trees, powerlines and unsecured structures and make driving difficult for high-sided vehicles and motorcycles.

Heavy rain warnings were also in place for the Headwaters of the Canterbury Lakes and rivers until 8am on Friday, and the Tararua Range until 1pm.

A road snowfall warning was also in place for Milford Rd (SH94) until 6pm on Friday, with the possibility of 2 to 5cm of snow accumulating by the tunnel.

The weekend was looking more settled, according to MetService, with some rain. The North Island would see a few showers in the west on Saturday, but be mainly fine while the South Island could expect rain or showers in the west and south with possible heavy falls.

On Sunday, MetService said rain would be developing in the west with possible heavy falls for the North Island and rain the west and south with heavy falls for the South Island.