The country will have a brief reprieve from unsettled spring weather with a couple of days of sunshine, before another active front sweeps over the South Island.

A weak anticyclone is moving over the country, bringing settled weather across much of New Zealand, MetService spokesman Daniel Corbett said.

However, the remnants of the weekend's southerly chill could bring overnight frosts to the North Island high country.

"Wednesday should start off fine and dry in many parts of New Zealand but another active front will spread more wind and rain to parts of the South Island,'' he said.

Westerly gales could pound the deep south of the South Island and ridges across Otago and Canterbury later tomorrow.

Rain could also be heavy and persistent across parts of Fiordland.

"High pressure to the northwest of the North Island will help fizzle out the active front as it moves across parts of the North Island but strengthening winds are still likely across the lower North Island late Wednesday into Thursday,'' Mr Corbett said.

The long weekend came to a cold and blustery end for many as snow fell in Canterbury, a tornado ripped through two small West Coast settlements and a cold snap moved up the country.

The unseasonable weather came with a cold southerly that brought snow as low as 200 metres to parts of Canterbury and gusts of up to 110km/h to Kaikoura.

In the the mid-Canterbury town of Methven, about 8cm of heavy snow settled overnight before thawing in light rain and sleet this morning, leaving roads clear but making gumboots a necessity.

A tornado flattened an old wooden theatre on the South Island's West Coast, tearing roofs off houses and shattering windows as it ripped through Hector and Ngakawau on Sunday night.

The twister struck about 12.30am on the Ngakawau River mouth, about 30km north-east of Westport.

- APNZ