Dunedin roads are likely to be affected today by a cold southwesterly expected to bring snow down to 200m.
MetService adviser Tuporo Marsters said this would probably mean a hazard for motorists entering Dunedin via the Northern Motorway. Snow was also likely to cover hill suburbs across the city.
It was expected to be ''significant'' above 300m and settle above 200m. Cold southwesterly gales were expected to accompany the snow.
Snow levels would gradually rise to above 500m by late afternoon or evening, he said.
The cold weather could cause stress to livestock. The MetService yesterday issued a severe weather watch for Otago, Southland and Fiordland.
Meanwhile, numbingly cold conditions are forecast for much of New Zealand early this week as a large storm in the Southern Ocean swirls away from the country.
Meteorologists are warning of plummeting temperatures on Tuesday, particularly in Dunedin, Christchurch and Wellington.
Auckland should stay relatively mild and sun might even be on the cards, WeatherWatch meteorologist Philip Duncan said.
The weekend's blustery winds should die off by Wednesday and easterlies rolling in will bring breezy and cloudy conditions, he said.
"It certainly doesn't feel like winter yet in Auckland. It's not a really bad week," he said.
"A lot of the storms that pass by us are huge at this time of the year...Dunedin, Christchurch, Wellington get it but there's a whole lot of land between there and Auckland so it stays kind of mild."
But the lower North Island and South Island might be a different story, Mr Duncan said.
Biting winds would bring a seriously cold day to Wellington on Tuesday with hail, sleet and snow possible, he said.
The city would have an actual high of 9 degrees but it would feel more like 4 degrees, he said.
Snow was also forecast for the hills of Dunedin and might reach the city streets but probably won't settle.
Temperatures should pick up again by Wednesday and stay relatively high until another cold snap comes through on the weekend, Mr Duncan said.
"Its not often that we have snow on our forecasts for Wellington city but Tuesday it is forecast in the region down to 400 metres.
"We call it a cold snap because it's not going to be causing major headaches across the South Island and while it is going to be winter...it should be sunny again by Wednesday and dry and we've got slightly warmer winds."
MetService meteorologist Nick Zachar said most people would see a "brief reprieve" in the middle of the week.
There was a series of cold fronts moving north over the next couple of days with showers plaguing much of the country, he said.
Severe frosts were possible in inland areas overnight on Tuesday and Wednesday and rainfall might reach warning criteria in the lower South Island on Thursday.
A ridge of high pressure was expected to reach the North Island by the middle of the week but another cold front would move across the country by Saturday bringing winds and a good chance of rain, Mr Zachar said.
Intermittent fronts sweeping the country were not uncommon for this time of the year, he said.
"We do get some big storms developing at this time of year...we can expect every few days a new storm system to move on through," he said.
The icy temperatures did mean good news for ski bunnies, with the official start to the ski season kicking off in parts of the South Island over the weekend.
Mt Hutt ski field in Canterbury opened its gates on Saturday alongside Queenstown's Coronet Peak and Wanaka's Cardrona Ski Resort.
The Remarkables will open on June 20 and Ruapehu's Turoa and Whakapapa ski fields are both in line to open on June 27.
This week's forecast:
* Dunedin: Showers with snow on hills. Cold winds with occasional rain developing.
* Invercargill: Sleety showers, with thickening high cloud and winds.
* Auckland: Occasional showers with winds easing to fine spells.
* Hamilton: Showers turning to fine weather with light winds.
* Tauranga: Fine with light winds. Evening cloud.
* Wellington: Showers, cold winds, sunny spells and cloud developing.
* Christchurch: Mainly fine with light winds and a few showers.
- additional reporting NZME
