A significant change is coming to New Zealand's weather pattern with at least 10 to 14 days of westerly winds dominating.

WeatherWatch.co.nz says this is "not your normal mid-winter pattern".

This more spring/autumn-like pattern means a variety of milder days and colder ones across the country with coldest air sticking to the south and warmest air sticking to the north.

"The dominant westerly flow will also mean a build up of rainfall on the West Coast while eastern regions stay dry to fairly dry."

This weather pattern means frosts are less likely over the next two weeks, although due to a polar southerly in the South Island today some frosts will be occurring this week in the calm spells.

WeatherWatch.co.nz says the westerly pattern is due to no big highs over the NZ area and instead keeping them stuck over Australia or to our north.

Sunday's weather pattern.

Australia, on the other hand, will continue to be smothered by a huge high for the next two weeks making their droughts worse, only a few rain bands will brush their very coastal fringes - the bulk of that rain will then be blown across the Tasman Sea to the West Coast and western Southern Alps of New Zealand.

Next Wednesday's weather pattern.