Settled weather is also in the forecast for most of the country as Kiwis head to the polls on election day tomorrow.

MetService says temperatures will be in the low to mid 20s on Sunday and Monday - far lower than the 40C predicted to hit some parts of Australia tomorrow.

MetService meteorologist Georgina Griffiths said: "It will be a mild, enjoyable and warm weekend, through to Monday and Tuesday for some parts of the country, which I'm sure will be welcomed after the weather we've had recently."

"We're looking at 36 hours of warmth for eastern regions of both the North and South Islands."

MetService forecast for temperatures in eastern parts of both Islands is in the range 23-25C.

"It's going to be a fairly, settled, warm weekend," said Griffiths.

Northwest winds strengthen over the South Island on Sunday and into Monday, bringing warmth to eastern regions. The North Island's eastern areas get the winds, and warmth, on Monday and into Tuesday.

Australia's Bureau of Meteorology, said it could be the first time inland New South Wales reaches 40C in September.

But Griffiths said it was unlikely any records would be broken here, although it could be up to 8C above average in some places on Monday.

"We will be getting enjoyable warm weather, but it won't be record-breaking and not quite a heatwave," Griffiths added.

The record September temperature at Christchurch Airport is 26.2C, Dunedin Airport is 24.9C and Napier Airport is 25.9C.

WeatherWatch forecaster Philip Duncan said tomorrow looked mostly settled around the country, with a low risk of severe weather.

"The weather shouldn't be an excuse for not voting in New Zealand's 2017 General Election," Duncan said.

"The weather is looking so settled we will have no need for extra updating across Saturday by the looks of it."

Election day weather

SOUTH ISLAND:

Few showers on Saturday, some rain around Fiordland will spread to South Westland for a time. Possible spits or showers in Southland and a chance of a few showers around Otago.

NORTH ISLAND: Few showers in Hawke's Bay and Gisborne, with possible heavier, more isolated inland showers near the ranges.

- WeatherWatch