Anyone hoping for a cooler night's sleep tonight can keep dreaming.
The MetService says: "Unfortunately, tonight is set to be another warm night for many.''
Many areas did not reach below 20C overnight, last night.
Overnight forecasts are mostly around the 16 to 18C mark in places including Auckland, Whāngārei, Gisborne, New Plymouth and Wellington.
People in the south can also expect warm conditions overnight; with Nelson expected to reach an overnight low of 17C, Christchurch 18C.
Those in Dunedin (14C) and Queenstown (15C) can breathe a little easier, while those in Invercargill might still need a blanket, with an overnight low 11C forecast.
The high temperatures come as a heatwave sweeps the country this week; bringing with it temperatures mostly in the late-20s to mid-30s.
Meteorologist Ravi Kandula said over the weekend that the heat would mostly be confined to the South Island - mainly central parts of Otago, Blenheim and Kaikōura.
Temperature highs in some of the main areas are forecast accordingly: Auckland 27C, Kaitaia 28C, Hamilton 30C, Whāngārei 26C, Napier 27C, New Plymouth 25C and Wellington 24C.
In the South Island, max temperatures expected are 26C in Nelson, 22C in Greymouth, 32C in Christchurch, 26C in Dunedin, 28C in Queenstown and 27C in Invercargill.
A statement released earlier today said a high over the country is due to move to the north tomorrow as north-westerly winds strengthen ahead of a front.
"The front moves onto the southwest of the country overnight tomorrow,'' MetService said.
Meanwhile Fire and Emergency New Zealand fire risk management national advisor Rob Goldring said the hot, dry and windy summer conditions increased the risk of fire and of a fire getting out of control.
"Due to current high temperatures, dry soil and vegetation, fire risk is extreme in Northland, Coromandel, Nelson, Marlborough and a total fire ban is in place for these areas," Goldring said.
Fire risk was also high and fire restrictions are in place in Auckland, Hawkes Bay, Bay of Plenty, Central North Island, Wairarapa, Southland/Otago and, as of yesterday, North Christchurch.
"If you are in one of these areas and thinking about lighting an outdoor fire, go to www.checkitsalright.nz to check your fire type and, if needed, apply for a fire permit."
He urged New Zealanders to be vigilant and follow these tips to keep safe:
• Clear house gutters and keep grass and other vegetation trimmed or short, especially around structures and boundaries with neighbouring properties;
• If you've had an outdoor open fire recently, physically check that the fire is fully extinguished and that there is no potential for them to reignite;
• When undertaking property maintenance that could cause sparks, for example mowing lawns and scrub cutting, avoid the hottest part of the day;
• When barbecuing, make sure barbecues are clean and that gas bottles are connected properly without leaks. See the soap bubble test: fireandemergency.nz/fire-seasons-permits/outdoor-gas-bbq/
For other fire safety tips visit FENZ at fireandemergency.nz/