MetService meteorologist Hannah Moes says the capital's had strong winds - with gusts recording at 117km/h after the front came from the south overnight.
She says there's also been torrential downpours, with 19mm of rain falling in the last hour.
The downpour has led to surface flooding on State Highway 1 south of Johnsonville and on State Highway 2 at Petone. Rail services on the Johnsonville line have also been affected by heavy rain.
SH2 PETONE, SOUTHBOUND - FLOODING - 9:40AM There is currently surface flooding in the left southbound lane prior to the Petone on-ramp. Please take extra care and watch your speed. ^EH pic.twitter.com/SVRcqW5xef
— Waka Kotahi Wellington (@WakaKotahiWgtn) July 13, 2019
SH1 JOHNSONVILLE ON-RAMP, SOUTHBOUND - FLOODING - 8:40AM There is currently surface flooding on the Johnsonville southbound on-ramp. Please take extra care and watch your speed. ^EH pic.twitter.com/k6msBcE8ZC
— Waka Kotahi Wellington (@WakaKotahiWgtn) July 13, 2019
A Wellington City Council spokeswoman said flooding was widely spread around the city, with the main affected areas Kilbirnie, Tawa, Khandallah, Strathmore Park, Roseneath, Newlands, Miramar, and Johnsonville.
"All reported incidents are logged with contractors so have either been fixed already, are being attended to, or they're on their way."
Fire and Emergency NZ shift manager Murray Dunbar said they had received about 10 calls in relation to surface flooding in Wellington.
In one instance a person drove into the floodwater on Kenmore St and could not move the vehicle, or get out of it, until the flooding was cleared, he said.
"There has been a little bit of surface flooding around Kenmore St and Bracken Rd in Newlands - that's been cleared by clearing the drains."
There was also a bit of flooding on Hutt Rd and in Tawa, he said.
Meanwhile fire investigators are looking into what caused a fire at a central Wellington motel this morning.
Seven fire appliances attended the blaze, which was contained to a single room at the Harbour City Motor Inn, on Webb Street.
Fire and Emergency New Zealand shift manager Murray Dunbar says crews were called at 8.08am. A specialist fire and emergency investigator is in attendance and the fire's been extinguished.
Cold front heading north, will hit Auckland later today
An active cold front with a band of heavy rain is moving quickly north from the South Island this morning to lie over the central and northern North Island.
MetService meteorologist Andrew James said some southern stations had recorded considerable rain overnight, especially in the western ranges.
Active fronts moving across the upper South Island and onto the North Island this morning. Severe Weather Warnings and Watches are in effect for many places for heavy rain and strong winds with todays weather system. Find the details at https://t.co/qHyE5zhh6X ^HM pic.twitter.com/SgoDvvs8eH
Both Arthur's Pass and Milford Sound received over 100mm in the past 18 hours, while a station at Cropp River had 173mm in the past 24 hours.
There is a strong wind watch in place for most of the North Island throughout parts of the day, including Northland, Auckland, Taranaki, Whanganui, Manawatū and Wairarapa.
Ideal conditions today for the formation of the Northwest Arch cloud east of the South Island ranges. There is a MetService blog on Mountain waves and clouds associated with turbulence here https://t.co/WoDXsi0gRT. ^AB pic.twitter.com/TLls4joD41
"So we are in this westerly pattern where we have got these features lined up and coming over the country again and again and again for the next week or so."
Main centre forecast
Whangārei Cloudy periods and a few showers, but rain around midday. Strong northerlies turn westerly afternoon. High 18C, low 8C
Auckland Rain around midday, otherwise showers. Thunderstorms and hail possible from evening. Strong northerly gust 90 km/h turning westerly. 17C, 10C
Hamilton Rain around midday, otherwise showers. Thunderstorms and hail from afternoon. Strong northerlies turning westerly afternoon. 16C, 6C
Tauranga Showers, but a period of afternoon rain. Strengthening northerlies turning westerly afternoon. 17C, 8C
Wellington Morning rain, briefly heavy, then a few showers, possibly thundery with hail. Northerly gales, gusting 120 km/h, easing from afternoon. 14C, 9C