A deluge has caused widespread problems throughout Wellington, with roads and shops flooded, power outages and flights disrupted.
By Monday night, 86.6mm of rain had fallen since 9pm on Sunday. However, MetService expects Tuesday to bring settled weather for Wellington and other parts of the country.
Almost all Air New Zealand domestic flights into Wellington were cancelled on Monday night due to strong winds, while five outbound services were delayed or cancelled.
Flood waters were at their highest just south of the Basin Reserve where traffic lights were out and fire crews had to pump water out of several buildings.
They included the Accident and Urgent Medical Centre on Adelaide Road, which also lost power and had to send patients up the road to Wellington Hospital.
In the northern suburb of Grenada, a crash has left one person dead and another seriously injured.
Police warned motorists to expect delays and drive carefully in the conditions. Buses were diverted around inundated roads throughout the day.
Meanwhile, a small earthquake centred in Wairarapa also jolted Wellington. The 3.8-magnitude tremor struck at 4.19pm at a depth of 33km. It was centered beneath Lake Onoke, 30km east of the capital.
About 900 homes in the suburb of Johnsonville were without power for a few hours on Monday night due to the bad weather. A spokesperson for lines company Wellington Electricity said the outage occurred at 6pm.
Earlier in the day, 134 central city homes and businesses lost power when a basement housing Wellington Electricity equipment was flooded. The company said power has been restored to all but one customer, whose switchboard was damaged.
Shops in the central city were flooded, while flooding also affected suburbs including Hataitai, Kelburn, Brooklyn and Karori.
Roads were closed and cars stranded in the suburb of Kilbirnie, and there was flooding near the Basin Reserve in Newtown. The Moa Point tunnel near Wellington Airport was also flooded.
In Alfred Street, off Adelaide Road, water almost reached windows of parked cars and workers in an office block were unable to get out of the building for a time.
There was also flooding on Grays Road, north of Porirua. Police said delays were expected and motorists should take care.
The Fire Service attended about 50 callouts in the space of two hours to clear stormwater drains and replace manhole covers. The Wellington City Council received more than 280 calls over a similar period of time with people asking for sandbags and for help unblocking drains.
Gales hit Auckland
Gales in Auckland on Sunday night, gusting up to 150 km/h in the west of the city, cut power to about 3000 properties.
Lines company Vector said power was restored to most places quickly overnight, but 100 customers in Muriwai were without power on Monday night.
In the South Island, heavy rain caused flooding and slips on a 5km stretch of State Highway 1 between Blenheim and Seddon.