A polar blast has hit New Zealand, bringing freezing temperatures and the heaviest snowfall in 40 years.

Snow is even predicted to fall on the hills around Auckland in what meteorologists are describing as a once-in-a-lifetime storm.

Schools across the country have been closed for the day and most airports are at a standstill.

The bitterly cold southerly blast has now brought snow to most of New Zealand, closing roads and some airports and cutting power to thousands of homes.

Snow has made roads impassable in many areas of both islands.

MetService head forecaster Peter Kreft told the New Zealand Herald the polar blast was "of the order of a 50-year'' event and warned it could last for several more days.

"It's a once-in-many-decades event. We are probably looking at something like, in terms of extent and severity, maybe 50 years,'' he said.

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