Wellington City Council is warning residents to stay off the roads as stormy weather and heavy rain has caused flooding in many parts of the city.
Its spokesperson, Richard McLean, said manhole covers have been lifted off in some places.
He said there is flooding in many low lying areas, including the CBD, Miramar and other eastern suburbs and also northern suburbs such as Johnsonville.
The weather has also disrupted some flights at Wellington Airport.
Niwa said heavy rain has also reached New Plymouth, and will reach other places including Hamilton, Tauranga and Auckland in the next few hours.
MetService said winds and rain are forecast to ease in Wellington, but also predicts the front will move further up the island.