A cold winter blast is hitting New Zealand this week which could bring historic snow to Christchurch and has already closed roads around the country.
NIWA said the combination of low temperatures and strong winds will produce a low wind chill on Wednesday and Thursday.
They warn the impacts of the weather will see livestock stressed from the cold and agriculture damaged from chilly temperatures and frost. Travel could also be affected because of snow and there could be a surge in electricity demand.
MetService is predicting Christchurch could see snow down to 200 metres on Wednesday morning and locals could even see snow at sea level in the evening.
MetService meteorologist Heath Gullery said the last time Christchurch saw an October snowfall was in 1969, NZ Herald reported.
Temperatures are forecast to plummet on Wednesday with Christchurch in for a chilly day with a low of -1C.
Further south, the Dunedin region will start with morning frosts on Tuesday but as the day progresses, the areas should see showers develop and turn to snow in the evening.
Snow is expected down to 400m in the Dunedin and Southland areas, and 300m in inland Otago.
Dunedin will see a chilly couple of days with Wednesday scheduled to reach a chilly 7C while Thursday is only slightly better with a high of 9C.
WeatherWatch said snow may impact all South Island alpine passes and black ice may also be an issue. Arthur's Pass could see a few brief snow flurries on Wednesday night, with overnight temperatures plummeting to -11C. Snow could also impact many highways and roads across Southland and Otago, WeatherWatch warned.
North Island
Heavy rain in Waikato and Wellington over the weekend has caused slips and flooding with more rain forecast on Monday.
Waka Kotahi New Zealand Transport Agency (NZTA) is warning driving conditions will be hazardous.
"Please only drive if essential. Due to the adverse weather, potholes are forming in multiple locations," NZTA said.
"Contractors are monitoring the situation, but in some areas, resources will be prioritised to clearing slips and opening roads.
NZTA said State Highway 25, Tairua Road, Hikuai is closed because of a slip, while stop/go is in place for SH25 2km north of Waikawau (Thames Coast), SH25 Te Mata to Waikawau (Thames Coast), SH2 Karangahake Gorge.
State Highway 33 from Paengaroa to State Highway 30, Rotorua is closed because of several slips and fallen debris.
Roads also closed in Wellington with a landslide blocking arterial road access to the suburb of Karori.
A large slip completely blocked a section of Birdwood Street, while Chaytor Street has been reduced to one lane with motorists told to use Old Karori Road/Whitehead Road and Curtis Street to enter and exit Karori as alternate routes.
Snow is also expected in the North Island with WeatherWatch predicting it in the Wellington hilltop suburbs, Masterton, Dannevirke, Taihape, Hunterville, Waiouru, Ohakune, Stratford and Turangi (or nearby).
"Snow may be mixed in with the rain but we could see some flurries below 200 metres in the North Island for a time on Wednesday night and early Thursday morning," said WeatherWatch.co.nz head forecaster Philip Duncan.
Snow to low levels in the North Island are unlikely to settle - or at least settle for long - but higher up could cause problems for State Highways 1 and 5 at higher elevations, WeatherWatch said.
WeatherWatch expects snow to settle on State Highway 1, the Desert Road and State Highway 5 the Napier-Taupo highway. State Highway 2 over the Rimutaka Ranges may also get a dusting, as might SH4 and SH49 around Mt Ruapehu.
