Boogie boards and beach loungers were in high demand over the weekend, with hundreds flocking to beaches to make the most of fine weather before a wet and windy turn this week.
Metservice said the east coast of both islands basked in hot temperatures, reaching the low thirties in both Napier and Christchurch.
In Auckland, Hamilton and Tauranga, the mercury reached 24C, however those further south were not as fortunate, with Wellington and Dunedin only reaching 20C today.
At Omaha beach, just north of Auckland, surf life saving club patrol captain Pete McCormick said beachgoers had enjoyed a "scorcher'' of a day.
Calm water conditions had made it ideal for swimmers, with more than 400 people on the beach at its busiest period, he said.
The warm weather had also left a few people at Auckland's Muriwai beach with burnt feet.
Surf life saving club patrol captain Christopher Butt said just under 1000 people had been at the beach this afternoon.
"Sea temperatures have been very warm today and we've had a few people with hot feet and a couple of anxious dogs.''
At Pauanui beach in the Coromandel, crowds had swelled to nearly 600 this afternoon.
Volunteer surf life saver Georgia Frew said conditions had been ``lovely'', with hundreds out to make the most of the flat beach conditions. A shark sighting yesterday had closed the beach for about an hour, however people were happy to return after that, she said.
In the Bay of Plenty, the popular Mount Maunganui beach had been packed with more than 1000 beachgoers today.
Crowds at all the beaches had been well behaved.
Weather across the country is expected to take a turn for the worse tomorrow, with remnants of Cyclone June from New Caledonia bringing rain and strong winds.
Met Service forecaster Elke Louw said the first part of the week would be miserable for many areas in the North and South Islands.
Rain and windy conditions would hit the upper North Island late tomorrow and spread to southern and central parts of New Zealand on Tuesday.
While heavy swells along the east coast, from Cape Reinga to the Bay of Plenty, were also possible on Tuesday, weather conditions were not expected to reach a level where weather warnings would be needed for affected areas, Mrs Louw said.
She recommended those keen to get back outdoors look forward to Friday, when dreary conditions were expected to clear for most of the country.
* Auckland: Showers on Monday and Tuesday, easing by Wednesday.
* Hamilton: Scattered rain on Monday, easing on Tuesday later in the day.
* Wellington: North-westerlies, cloudy conditions on Monday. Rain on Tuesday with heavy falls possible.
* Christchurch: Cloudy with easterlies in the afternoon on Monday. Rain and drizzly conditions on Tuesday.
* Dunedin: Fine on Monday with cloudy, drizzly conditions developing in the afternoon and continuing through to Tuesday.