Weather: Snow blasts, thunderstorms, hail, tornado on first day of winter

It's only the first day of winter, but already its delivering blasts of snow, thunderstorms, peltering hail, and a tornado.

Meteorologists warned this Queen's Birthday weekend would be a chilly one and a dramatic move away from a mild May and relatively warm autumn.

Those in the Canterbury region woke to blankets of heavy snow transforming their gardens into winter wonderlands.

It was the result of an active low pressure system barrelling its way up the country overnight. Mt Hutt ski field saw 60cm of snow on Saturday morning. Ski fields in the region will start opening from June 7.

The Canterbury Weather Updates Facebook page said snow had fallen to 200m with significant falls around higher areas.

Rain triggered a rockfall on State Highway 1 south of Kaikōura at 1pm on Saturday leading the NZ Transport Agency (NZTA) to close the road between Peketa and Oaro.

The Arthur's Pass to Springfield route and Lewis Pass were also closed for a period of time but have reopened.

Further north, snow flurries have also affected higher parts of the Central Plateau and Desert Rd on Saturday, according to WeatherWatch. MetService says "unstable westerlies" also pelted the North Island with heavy rain and gusts of wind.

Those in west Auckland were slammed with large hailstones overnight after an "intense burst of thunderstorms came off the Tasman Sea" on Friday evening. Hail on Saturday was much smaller and there could be some on early Sunday.

The strong winds led MetService to warn mariners in Auckland to take note.

A tornado was even filmed near the Whangaehu Coast on Saturday morning, with a witness telling Newshub it was a couple of hundred metres tall and lasted a few minutes.

The peak of the cold polar air likely won't be felt until Saturday night or on Sunday for the North Island.

June 1 marks the first day of winter on the meteorological calendar.

Newshub.