A Severe Weather Watch is in force with severe gales and heavy rain expected across New Zealand.

Westerly gales are easing over the upper North Island, following Saturday's westerlies, says a MetService spokesperson.

"Gales and rain return to southern and central areas on Monday."

Strong westerlies over the upper North Island were easing on Saturday evening, as a trough moves away to the east.

MetService says another broad trough is expected to bring strong winds to southern and central parts of the country on Monday, with brief heavy rain for the west of the South Island.

People are advised to keep up to date with the latest forecasts in case more areas are added, or watches are upgraded to warnings.

Heavy Rain Watch
Area: Buller
Valid: 8 hours from 8:00am Mon 2 Oct to 4:00pm Mon 2 Oct
Forecast: A period of heavy rain. Rainfall amounts may approach warning criteria about the ranges.

Area: Westland
Valid: 12 hours from 3:00am Mon 2 Oct to 3:00pm Mon 2 Oct
Forecast: Heavy rain. Rainfall amounts may reach warning criteria about the ranges.

Area: Fiordland
Valid: 10 hours from 1:00am Mon 2 Oct to 11:00am Mon 2 Oct
Forecast: Periods of heavy rain. Rainfall amounts may approach warning criteria, especially about the ranges.

Strong Wind Watch
Area: Marlborough Sounds, Wellington, Wairarapa, Tararua District and Hawke's Bay south of Hastings
Valid: 12 hours from 6:00am Mon 2 Oct to 6:00pm Mon 2 Oct
Forecast: West to northwest winds may reach severe gale in exposed places.

Area: Canterbury Plains, Banks Peninsula, and coastal Marlborough south of Ward
Valid: 10 hours from 5:00am Mon 2 Oct to 3:00pm Mon 2 Oct
Forecast: Northwest winds may approach severe gale in exposed places.

Area: Inland Fiordland, Southland including Stewart Island, and Clutha
Valid: 14 hours from 12:00am Mon 2 Oct to 2:00pm Mon 2 Oct
Forecast: Northwest winds may reach severe gale in exposed places.

Note, a change to southwest gales is likely at the end of this period.

Area: Canterbury High Country
Valid: 13 hours from 3:00am Mon 2 Oct to 4:00pm Mon 2 Oct
Forecast: Northwest winds may reach severe gale in exposed places.

Area: Otago excluding Clutha
Valid: 12 hours from 3:00am Mon 2 Oct to 3:00pm Mon 2 Oct
Forecast: Northwest winds may approach severe gale in exposed places.

Watches no longer in Force
Strong Wind Watch lifted for Northland : Winds are easing, and the watch has been lifted.

Strong Wind Watch lifted for Auckland including Great Barrier Island, and Coromandel Peninsula : Winds have eased, and the watch has been lifted.