A deluge of rain has saturated parts of Northland, with the rest of the country told to brace itself.
Two homes in the Coopers Beach area have been flooded, with the heavy downpour keeping fire crews on their toes.
Weatherwatch expert Richard Green says it's going to be a nasty weekend.
"I'm looking at the rain radar and 85 to 90 percent of the North Island is covered by some moisture, with the exception of Gisborne and Hawke's Bay."
An active trough is expected to move southeastwards across the North Island early tomorrow morning, causing a brief spell of heavy rain and north to northwest gales, according to the MetService.
Localised downpours and northerly gales are expected in central New Zealand too.
Slips in the Manawatu Gorge are being cleared, and motorists are being asked to take extra care while contractors work to clear the road.
Currently, two slips within 150 metres of each other have occurred due to torrential rain in the last few hours.
The westbound lane is blocked with debris; however the eastbound lane has now been opened back up to traffic.
There is significant congestion through the gorge expected to last a few hours.
Wellington motorists haven't escaped unscathed either as torrential rain and flooding makes for difficult driving conditions.
As a result of the weather, several crashes have occurred. The Northbound lane of State Highway 1 near Churton Park has surface flooding which caused a minor crash at Whitby.
And in another instance, a car has spun out on State Highway 2 around 100 metres south of the Haywards Hill intersection.
One south-bound car crossed the centreline and hit a northbound car on State Highway 1 near Paekakariki just before 8:30am. The car then bounced off another north-bound car.
As a result, a person has been taken to hospital with serious leg injuries, and others involved in the crash appear to have suffered minor injuries.
Meanwhile, in the South Island Mr Green says an icy weather event is forecast.
The Otago Regional Council is warning residents about snow, telling them to prepare for a cold weekend.
Snow is falling to about 400m in parts of Canterbury and is expected to ease later this morning.
Warnings for heavy rain remain in force for the Richmond and Bryant ranges, Rai Valley and Buller.
Director of engineering, hazards and science, Dr Gavin Palmer says it will affect much of the region.
"We will be keeping an eye on eastern Otago, around Dunedin and a little bit further north as well."
The MetService says severe northerly gales are expected to ease in Northland, Auckland, Taranaki, Whanganui, Taihape and northern Manawatu, but the warning remains in force with gusts of 120 km/h possible until around midday.