Weather forecaster Niwa has predicted a high of 26C in Invercargill on Tuesday, topping Kaitaia's high of 21C.
Meanwhile, MetService has capped the temperature in the Southland town at 22C with a low of 11C.
But neither forecaster is picking that the warm temperatures will stay around for long.
Niwa picks the temperature to drop to 16C on Wednesday and 14C on Friday, while MetService predicts 18C on Wednesday and 17C on Friday.
Warm weather is forecast by Niwa in Queenstown as well on Tuesday, with a high of 24C and a low of 9C Tuesday.
Niwa's highs across the North Island are Auckland, Hamilton and New Plymouth at 19C, Taupō, Napier and Palmerston North at 17C and Wellington 16C.
In the South Island, Niwa forecasts highs of 17C for Nelson and Oamaru and 18C for Greymouth and Christchurch.
It follows a dramatic week of weather across the country - with hail storms battering parts of New Zealand, and even certain suburbs in Auckland, while others remained sunny.
Summer thunderstorms dumped heavy hail and torrential rain sparked flash flooding in the upper South Island on Boxing day, causing extensive crop damage.
Heavy hail blanketed Motueka on December 26, with a tally of the damage it caused to orchards in the area by an industry association in the millions.
Richard Clarkson, president of the Motueka Fruit Growers Association, said some growers had lost their entire crops, RNZ reported.
Meanwhile, on Sunday, a burst of hail in the central North Island made some residents' backyards look like they were coated in snow.
Tauranga resident Justine Laidlaw said her Oropi home was hammered with a "freak hailstorm" on Sunday, which lasted for about 30 minutes.
'My vegetable garden looks a bit worse for wear; courgettes, tomatoes, and other plants have been hammered.
"But Nelly the 5-month-old puppy, thought it was heaps of fun afterwards."
MetService: Tuesday's weather
Kaitaia Mostly fine, chance showers until evening, southwesterlies. 21C high, 13C low.
Whangārei Fine, southwest breezes. 23C, 13C.
Auckland Fine, fresh southwesterlies. 20C, 14C.
Hamilton Fine, chance afternoon shower, southwest breezes. 21C, 8C.
Tauranga Fine, fresh southwesterlies. 24C, 12C.
New Plymouth Fine, some morning cloud, southwesterlies. 21C, 9C.
Rotorua Fine, southwesterlies. 20C, 9C.
Napier Fine, southwesterlies. 20C, 12C.
Wellington Cloudy periods, southerly breezes.16C, 10C.
Nelson Fine. Northerlies developing in the afternoon. 18C, 11C.
Christchurch Areas of cloud developing at night, northeasterlies, fresh from afternoon. 18C, 10C.
Dunedin Some morning and late evening cloud, fresh northeasterlies, strong afternoon and evening. 18C, 12C.
