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Heavy snow has been falling to sea level in Timaru for several hours and has now spread across inland Canterbury to Christchurch, according to The Radio Network's South Island weather analyst Richard Green.
But despite today's chilly conditions, last night was the warmest overnight low on record in Christchurch, said Mr Green.
"It dropped to only 15.7 degrees (overnight) thanks to the nor'wester," he said, adding that the average overnight low for Christchurch in June was 0.8 degrees.
Motorists in Southland Otago and Canterbury are being warned to take extreme care as snow, hail and sleet have made driving conditions dangerous.
The severe gale force winds predicted have eased but heavy snowfall is still on the agenda for parts of the country as a cold front makes it way across New Zealand.
The Radio Network's head weather analyst Philip Duncan says the South Island and lower North Island have been battered by very strong winds with gusts of more than 150 kilometres an hour recorded at Castle Point and Stewart Island.
The winds in the Wellington hills have dropped back to about 100 kilometres an hour.
Mr Duncan says the wind chill factor will be a particular feature with daytime temperatures of three degrees already recorded in Invercargill today.
Snow to sea level is also expected in other parts of the South Island, with Mr Duncan predicting falls for Kaikoura and Banks Peninsula.
The front will hit the North Island tonight and could result in snow across the Rimutaka Ranges and the Desert Road through the central North Island.
"We're warning motorists in the North Island to take extreme care tonight and tomorrow morning," Mr Duncan said.
"Snow is expected on the Rimutaka Ranges and possibly the Napier Taupo Highway.
"Heavy snow is also likely on the Desert Road and there's a good chance it may be need to be closed."
Coastguard officers around the country said if boaties could still get to their boats in exposed moorings they should check the moorings before the weather turned too nasty for them to get out.
In Wellington, where the All Blacks were to play their first test tonight since being tipped out of the World Cup in the quarter final by France last year, the harbour was reported to be rough and boisterous as the wind gathered strength.
The threat of bad weather had persuaded boaties to stay at home in all main centres and coastguard officers said it was very quiet on harbours and coastal areas.
The MetService said such strong winds could lift insecure roofs and were likely to cause hazardous driving conditions, particularly for high sided vehicles, motorcycles and cars towing caravans.
It said the front would be followed by a wintry blast with very cold, showery southwesterlies along eastern coasts.
- NZPA, NEWSTALK ZB
