"Probably most people on Monday will have a slightly better sleep. The temperatures certainly take a dip," WeatherWatch analyst Philip Duncan said.
He predicted a pause in the humidity affecting the upper North Island on Monday and into Tuesday following a "refreshing" southeasterly change.
The change would push the moist air to the east of the country, only to be pushed back from Tuesday night by an easterly flow and showers. A day-time high of 27C is forecast for Auckland and parts of Hawke's Bay and Waikato tomorrow.
Whangarei is expected to reach 26C and a high of 21C is forecast for Wellington.
Isolated downpours are forecast for vast areas of the North Island, with the heaviest bursts in Coromandel and eastern Bay of Plenty.
Duncan said South Islanders should expect a colder change. Dunedin should see 13C on Tuesday, a huge contrast to yesterday's 33C in Christchurch. But in good news, summer conditions should return by mid-week.
"It has been a weird summer," said Duncan. "All the talk of El Nino hasn't happened. It's almost like La Nina, the complete opposite."
Two fronts are coming through in the first and second weeks of March.
"Overall, it encourages more northeasterlies for the top of the country," he said.
The South Island can expect more westerlies and rain on the West Coast.