Weather: Not just hot, it's going to be a heat wave

It'll be a scorcher of a weekend and some parts of New Zealand could officially be facing a heat wave next week.

Many towns, especially in the eastern parts of the country, will see consecutive 30C days from Sunday tomorrow through to the end of the week, MetService says.

A heat wave is defined by the World Meteorological Organisation as having five or more days in a row with temperatures that is 5C above average.

A ridge of high pressure, trapping warm air over New Zealand, is the cause of the oven-hot temperatures.

"The warm, humid air is also going to make for some sultry nights, with overnight minimum temperatures in the high teens, and Nelson, Tauranga and Auckland not even cooling below 20C for a few nights," a MetService said.

There's high pressure over the North Island and strong northwest winds down south.

"These northwest winds are going to drag some very warm air across the Tasman setting us for a scorching week," MetService said.

WeatherWatch.co.nz is also forecasting for many regions to hit daily highs of between 27 and 32C.

The weather looks to be consistently warm throughout the work week, but there could be a cool reprieve in the deep south late Thursday or early Friday.

People heading out for the many sporting and Auckland Anniversary events over the next few days are advised to use ample amounts of sunscreen, drink plenty of water and keep in the shade where possible.

Your Saturday weather

Northland, Auckland, Waikato & Bay Of Plenty: Mostly sunny with some mid and high level cloud. Highs: 24-26

Western and Central North Island: A mix of sun and cloud with northwesterly winds. Highs: 21-23

Eastern North Island: Mostly sunny with some high cloud, northwesterlies. Highs: 25-28

Wellington: Sunny spells with northerly winds. High: 21

Marlborough and Nelson: Sunny areas and some high cloud, afternoon north to northwesterly winds. Highs: 25-29

Canterbury: Sunny areas and some high cloud, northwesterlies for most however tending northeast about the coast. Highs: 25-28

West Coast: Mostly cloudy about South Westland with patchy rain or showers, winds from the northeast. Highs: 19-23

Southland & Otago: A cloudy morning for Southland with some scattered rain, it may dry out for a time in the afternoon. Highs: 22-25

Source: WeatherWatch.co.nz