The best places to be are from Northland through Auckland to central areas, and the Coromandel and Bay of Plenty, where light southwest winds and warm temperatures up to 25C are forecast.
WeatherWatch NZ reported some spots around Gisborne and Napier hit 32C on Tuesday, over 8C above the average temperature.
Yesterday Metservice's temperature gauges had Napier topping the country on 28C, and neighbour Hastings close behind on 27C.
Those areas are in for a slight cooldown today, dropping to 23C with the southwest change.
A small front is approaching the South Island, making landfall tomorrow morning and could bring periods of rain to parts of the lower South Island and West Coast.
There may be a few showers in eastern areas overnight Friday, but the front will weaken as it moves onto the North Island.
"At this stage it does not look like there will be any significant weather with that front," Loots said.
During the second half of Saturday another big high will form and the weather will quickly become fine.
On Sunday a similar system will pass over the lower South Island, scattering rain through Fiordland and the West Coast.
But the main weather system to keep an eye on was a "very cold" southerly storm due to arrive early next week, Loots said.
"No severe weather is forecast until that system late Monday and into Tuesday.
"At this stage it looks like it could be a snowfall event with much cooler conditions: the first real autumn blast of the year."
WeatherWatch NZ says the cold snap could plummet maximum temperatures across both islands, with some areas in the North Island forecast to be 13C colder than they were earlier this week.
Daily highs in central areas in the South Island could drop into single digits.
MetService's outlook for April forecasts "an unsettled period for both Islands", starting with next week's storm.
There may be a quiet spell mid-month, but active weather is likely to return in the third quarter.
Overall it is likely to be a very wet month for the West Coast of the South Island and Southland, and normal to above normal for Taranaki down to Wellington.
North of Taupo is forecast to be drier than usual, but elsewhere should see normal levels.
Temperatures are forecast to be much closer to average than the first three months of the year, when they have been 1.75C higher.
Tropical Cyclone Iris, which had been threatening the Queensland coast this week, has been downgraded from Category 2 to 1.
The Queensland Bureau of Meteorology has cancelled a tropical cyclone warning for the region as the system moves further out into the Coral Sea today.
Today's weather
Whangarei Morning cloudy periods then fine. Southwest breezes. 23C high, 14C overnight.
Auckland Fine apart from morning cloudy periods. Southwesterlies. 23C high, 13C overnight.
Hamilton Fine. Gentle southwesterlies. 23C high, 10C overnight.
Tauranga Fine. Light winds. 25C high, 14C overnight.
New Plymouth Morning cloud, fine spells increasing afternoon. Southwesterlies. 22C high, 11C overnight.
Napier Fine, but cloudy periods developing late afternoon. Light winds. 23C high, 12C overnight.
Wellington Mainly fine, morning cloud with a southerly change. Northerlies return evening. 20C high, 14C overnight.
Nelson Fine with light winds. 21C high, 10C overnight.
Christchurch Fine apart from morning cloud. Northeast breezes. 18C high, 7C overnight.
Dunedin Fine. Northerly breezes. 21C high, 11C overnight.
