Buller is on alert for severe gales forecast tonight, which could be damaging.

Local civil defence report the West Coast region, and North Westland, will be in a "squash zone" between two weather systems overnight.

The strongest winds are forecast for Buller from about midnight, where severe gales with damaging gusts of 140 kilometres an hour are forecast.

Buller Civil Defence said gusts could possibly exceed this around western areas north of Westport.

It warns winds of this strength could damage structures, power lines, and make driving hazardous.

People are urged not to venture outside during the extreme conditions as loose material picked up can become missiles.

Locals are advised to secure their property and trampolines or any other loose outdoor items.

Civil defence has also advises locals to have their emergency kits ready, check household food supplies and have torches in case power is lost.

The winds will not begin to ease until tomorrow afternoon.