Wellingtonians are being urged to stay away from the South Coast today with huge waves set to hit the shoreline

High tide is at 8.30 this morning, and will give the first indication of what's in store.

Waves of six metres are forecast, with the largest expected this evening.

Wellington Region Emergency Management Office spokesperson Jeremy Holmes says homeowners need to be on standby to evacuate, and everyone else needs to steer clear.

He says people need to stay off the beaches and out of the water, and anyone driving on coastal roads needs to take extra care as there may be debris, water and damage.