Residents along parts of Wellington's south coast are being told to prepare in case they need to evacuate their homes tonight.
Wild weather is lashing the area, with gusts of up to 100km/h and 6m swells expected overnight.
The strongest winds are expected to coincide with the next high tide at half past one in the morning.
Wellington City Council says residents of Owhiro Bay - where properties were damaged and homes evacuated during huge swells in April - need to be ready to safely leave their homes if the weather gets bad enough.
It said it has cleanup crews on standby if necessary, and it was asking people not to put out recycling this evening and to tie down trampolines.
MetService meteorologist Kyle Lee said the worst of the southerlies would hit from 6pm and peak around midnight.
"Because of the strong southerly surge we are also expecting combined waves and swells to get up to five-and-a-half, maybe even six-and-a-half, metres for the south coast this evening in Wellington - unfortunate timing in terms of maximum swell and combined waves."
After huge waves hit the coast in April causing damage to homes a wave warning system was brought in to alert councils and civil defence.
Some Owhiro Bay residents were boarding up their windows and moving their vehicles early this evening in preparation.
Isaac Shanley - who's house is still being repaired after the April storm - said he has lifted electronic items off the floor in case the property gets flooded again.
He said it was an anxious time.
"We're going to stay here as long as we see that it is okay, if not we'll probably [leave and] go to different houses."
But Doug Van Boheemen, who has lived in Owhiro Bay for a decade, said weather like this happened at least once a winter and he did not expect there to be much damage.