"Summer holidaymakers in the Far North can rejoice, as the weather there is definitely set to 'summer mode' for the rest of the week," MetService said.
Elsewhere, residents and tourists on the East Coast are likely to flock to the beach as the thermometer jumps above 30C today and tomorrow, although showers and cloud will likely bring a sharp drop back to the low 20Cs by the weekend.
Clouds, wind and light showers are expected to stop Wellingtonians joining in the summer fun today as temperatures are only expected to reach a high of 22C.
In the South Island, Christchurch can expect a summery 28C before a change drops temperatures down to the low 20s from tomorrow.
MetService said a moist front would hit Fiordland in the country's far southwest this morning, before moving across the rest of the South Island during the day.
The front had also led the forecaster to issue heavy rain warnings for Fiordland and Westland overnight.
Your weather today
Whangārei: Fine, some high cloud. Light winds. High 28C Low 18C
Auckland: Fine with high cloud, but isolated afternoon showers. Light winds. High 27C Low 17C
Tauranga: Cloudy at times. Northerly breezes developing. High 25C Low 17C
Whanganui: Cloudy at times. Northwesterlies picking up this morning. High 27C Low 18C
Napier: Fine, high cloud developing this morning. Northwesterlies. High 31C Low 18C
Wellington: Mostly cloudy, possible light showers. Strong northerlies. High 22C Low 17C
Christchurch: Cloudy periods. Possible shower this morning. Northwesterlies change southerly early afternoon. High 28C Low 12C
Dunedin: Morning cloud clearing to fine. Southwesterlies. High 20C Low 12C
Source: MetService
