Somebody has turned the heat on.

A week ago, the country was still feeling the spring chill with temperatures in the main centres loitering around the mid to late teens. Then summer arrived.

With the sun out and the wind down, Auckland, Hamilton and Wellington have been basking in temperatures past the 20C mark - with MetService recording 22.9C in Hamilton and 22.5C in Auckland on Thursday. Only Christchurch let the side down, barely nudging past 19C.

The warm weather has prompted many to fire up the barbecue or head to the beach for their first summer swim.


Auckland project manager Stuart Turner's wife and children were among those in the water at Mission Bay yesterday.

He wasn't quite ready to join them but conceded there had been a definite change in the weather, especially on Friday.

"It actually seemed like summer," he said.

WeatherWatch forecaster Philip Duncan wasn't ready to call the change of the season, but said there were signs it was just around the corner.

"We are definitely seeing a gradual increase in temperatures and it's making for pleasant days and evenings, but we're still getting cold nights."

And the good weather should continue - especially for those on the east coast and in central areas, with the first hot nor'west winds expected to blow in from Australia late this week.

That could push temperatures up to 30C in some places, Duncan said.

Meanwhile, the Auckland Council has good news for the beach-bound with nearly all city beaches passing their first water-quality tests for summer.

Sixty-four of the 69 beaches tested were deemed safe to swim in.

Only Pah Beach on Great Barrier Island needs to be checked again after failing the test, while four beaches are subject to permanent warning notices.