The bad weather has also caused flooding on the West Coast, with ten people needing to be evacuated from their homes.
Flights at Dunedin airport have now resumed after 10 flights were cancelled this morning.
Dunedin International Airport chief John McCall says the cold blast caused significant disruption this morning.
He said operations had to be suspended entirely with significant black ice on the runway and disruptions to the national network causing five arrivals and five departures to cancel.
Mr McCall said the airport is now functioning but airlines will have a backlog of passengers to accommodate.
The city is experiencing its first real day of winter, but has missed out on heavy snowfall.
The Dunedin city centre is relatively snow free while the hills and outlying suburbs have borne the brunt of the cold blast.
Dunedin Police Senior Sergeant Bruce Ross said there had been a few minor traffic incidents mainly caused by black ice.
He says there was probably a late freeze, the temperature at 9am was minus 2 degrees, but warmed up to five degrees.
The Otago Regional Council suspended bus services on the hill areas this morning because of snow and ice but these have resumed.
Snowfall overnight created difficult driving conditions throughout South Otago. Police and local authorities urged motorists to take extreme caution throughout the Clutha district, but all roads remained open.
Danseys Pass is closed by snow. All other roads in Central Otago are open although roading authorities are warning motorists to be careful because of snow on Poolburn, Naseby, St Bathans and Ranfurly roads.
On the West Coast heavy rain and winds have also caused road closures throughout the district.
The Grey District Council says home owners near Coal Creek have had to be relocated, and Range Creek also burst its banks, affecting lower Cobden but is so far is not threatening any homes.
The council said there is localised flooding in Packers Quay, Preston Road and Coakley Street, Blaketown; Shakespeare Street and Alexander Street.
State Highway 6 from Greymouth to Runanga is also closed due to flooding.
The council said there is no risk of the Grey River flooding at this stage.
Fifty sandbags remain in place in Murchison, but flood waters appear to be receding, according to the Nelson Tasman Region Civil Defence and Emergency Management Group.
Flooding on Faifax and Hampden streets affected one commercial property, one residential property and the recreation centre, however this has been cleared.
Civil Defence said there are also a few slips have been reported around Longford and hills in Murchison, but no roads or property is in danger.
In Nelson, Isel Park is closed due to windy conditions and the risk of falling tree branches. Tahunanui Reserve back beach is also closed due to storm tide debris and risk of falling tree branches.
Winds with gusts up to 130kmh are forecast to lash the Tasman region
Snow has been reported in Rappahannock, Matakitaki and Tophouse, but not at a level to cause concern. Korere-Tophouse Road was closed near Tophouse after a truck and trailer unit lost control in about 10-40mm of snow, blocking the road.
Snow meanwhile is still falling across much of Canterbury, including Hanmer Springs, Twizel, Burnham, Kirwee, and West Milton.
It's also fallen to ground level in Christchurch city with 10cm reported in the central city and up to 15-20cm out by the airport.
Christchurch Airport remains open, however flights have been delayed. A spokeswoman said runways are being cleared of snow and she advised passengers to check the status of their flights with individual airlines.
Approximately Orion 400 customers in parts of Harewood, West Melton and McLeans Island are without power due to the weather and a car collision with a power pole. The company says teams are working as quickly as possible to restore power.
Metro buses have had to alter routes in Christchurch due to the snow, with services stopping at the bottom of hill roads.
New Zealand Post has had to suspend the delivery of mail in Greymouth and its outlying areas, Rangiora and Kaiapoi, Ashburton and Christchurch, due to the weather. Delays are also expected to mail deliveries in Westport, Gore and Balclutha.
MetService said a deep lower is expected to approach the upper South Island from the west this morning, then weaken slightly and pass east over the central North Island tonight.
A cold front, which is bringing heavy snow to Canterbury and parts of Marlborough and heavy rain to Westland, Buller, Nelson and the north of Marlborough, sits about Cook Strait and is expected to move north.
Heavy rain warnings are in place for Westland north of Hokitika, Buller, Nelson and Marlborough north of Seddon, with 80mm to 120mm forecast in the 18 hours from 6am.
MetService is also warning of strong winds - up to 130kmh in exposed areas - about Nelson, Buller and Westland.
