NZ weather: Auckland could hit low-20degCs as sun warms country this week

After a week of wintry cold gusts and heavy snow, the sunny weather is back for most of the country - just as the kids go back to school.

While the North Island can expect a mostly summery Monday, rural inland areas in the Central Plateau and East Cape will potentially face a frost to start the day, forecasts WeatherWatch.

But that won't last long, with morning cloud and breezes dying away for warm temperatures across the island in the afternoon. Auckland and the Bay of Plenty could reach the early 20degC, WeatherWatch says.

The South Island can expect a similarly warm day, though there will be some cloud about Southland. Light winds will twirl their way onshore in the afternoon.

The highest temperatures there will likely be recorded in Nelson, Marlborough and inland areas in the lower part of the island.

Warmer weather comes as an enormous high pressure system in the Tasman Sea moves up the country over the next 10 days.