Summer arrived a month early for much of the country over the long weekend.
Humid conditions bolstered temperatures in the upper North Island to the low 20s, with eastern areas of the island reaching the mid-20s.
The weather was fine in Auckland with light winds, the City of Sails reaching a balmy 22C. Hastings, meanwhile, was the warmest place yesterday, reaching 26C.
Coastguard spokeswoman Julia James says they were busy on the water yesterday but there were no major rescues or events.
Surf Life Saving chief executive Paul Dalton also said there was nothing major brought to his attention yesterday.
Weather-wise, the east coast of the South Island was the cream of the crop, with Christchurch, Dunedin, and Kaikoura reaching 29C on Sunday.
The sweltering conditions added to an already warmer than usual October for the likes of Christchurch, which has had five days over 25C when it normally only gets one.
The springtime scorcher was short-lived for some though, the temperatures plummeting 10C
for those on the South Island's east coast overnight on Sunday.
And if you didn't make the most of the great weather, you'll be disappointed to learn the cool weather shift is set to stay for much of the week.
The front that moved over the South Island yesterday will continue to move north, Crabtree says.
"Rain will develop over lower parts of the North Island overnight, Wellington, Kapiti, Wairarapa," she said.
"Tomorrow, lower parts of the North Island will have some wet weather and up towards Waikato, Bay of Plenty, tonight might start to see a shift in weather."
In the main centres, Auckland should expect a partly cloudy day with light winds and the temperature to reach the low 20Cs.
Tauranga can also expect fine spells with northerly breezes which will turn southeast at night for a high of 21C. Rain will ease in the Capital for a high of 13C.
Christchurch will break out to a fine afternoon and 13C also, with Dunedin due to experience the same: morning cloud with a chance of showers before becoming fine and also reaching 13C.
After boasting some of the hottest temperatures on Sunday, lower parts of the east coast of the South Island were the coolest yesterday. Places like Dunedin and Timaru barely managed to reach the mid-teens.
Heavy rain warnings are in place for the headwaters of the Canterbury lakes and rivers south of Arthurs Pass this morning, Westland until tonight, and Buller until tomorrow morning.
"We have a bit of a break in the weather during the middle part of the week and then towards the weekend, temperatures start picking up again - back up into the 20C's on Friday," Crabtree says.
Whangārei: Fine spells, but a possible afternoon or evening shower. Light winds. High 24C, Low 14C.
Auckland: Partly cloudy. Light winds. 22C, 14C.
Tauranga: Fine spells. Northerly breezes, turning southeast at night. 21C, 13C.
Hamilton: Fine spells. Northwest breezes. 22C, 11C.
New Plymouth: Rain developing in the morning. Northerlies changing southeasterly by evening. 19C, 10C.
Napier: Cloud increasing. Rain from early afternoon with westerlies changing southerly. 20C, 10C.
Wellington: Rain and an early morning change to fresh southerlies, all easing later in the evening. 13C, 9C.
Christchurch: Mostly cloudy, with rain or drizzle clearing in the morning. Fine spells in the afternoon. Southerlies gradually dying out. 13C, 3C.
Queenstown: Morning cloud then increasing fine spells. Southeasterlies dying out in the evening. 14C, 3C.
Dunedin: Morning cloud with the chance of shower, becoming fine in the afternoon. Light winds. 13C, 7C.
Invercargill: Morning cloud with a few showers possible, becoming fine from afternoon. Southeasterlies developing in the afternoon. 14C, 2C.