Ahh, summer… enjoy it while it lasts

A high pressure system brought warm temperatures to much of the North Island yesterday. Picture / Martin Sykes

With almost perfect timing, much of the country basked in warm, sunny weather for the first day of the school holidays yesterday - and with luck, the fine spell could hang around for at least another day.

A high pressure system is parked over the North Island, keeping at bay a front which is moving up from the South Island.

That should mean mostly sunshine and blue skies at some of the country's favourite holiday spots in Northland, Coromandel, Waikato, Bay of Plenty, Gisborne and Taupo today.

"After the cold, cold winter we've had it's nice to see some summery weather around although, dare I say it, in Wellington it's been dull and windy," said MetService forecaster Peter Little.

The lower South Island out-shone everyone yesterday, tipping the mercury at a sizzling 25C.

While Auckland and Kaitaia could reach only 20C and 22C respectively, Dunedin and Alexandra were the hottest spots on the map thanks to a blustery northwest wind blowing in from the Tasman sea which pushed hot air over the lower South Island.

Much of the North Island was covered in sunny, blue skies and warm temperatures. But Wellington, Taranaki and Manawatu missed out on the good weather with cloud and blustery winds.

Readings of ozone in the atmosphere showed that the layer of thin ozone - which had brought summertime UV levels to the country at the weekend - had moved on.

But the bad news is, the good weather won't last.

A cold front lying across the South Island will move north, bringing cloud and drizzle down south in the morning but clearing in the afternoon.

Things will deteriorate in the North Island from tomorrow with cloud, rain and drizzle forecast from Auckland to Taranaki.

And by Thursday, rain or drizzle and cloud will spread over much of the North Island.

Climate scientists believe a moderate El Nino weather pattern has developed over the Pacific which should bring lower rainfall and dry summer winds to New Zealand, especially in eastern parts.

An El Nino also means more southwesterlies over the South Island and average temperatures for summer over the country as a whole. The Pacific Islands face an increased risk of tropical cyclones.

Sea temperatures have been warmer than normal around the Equator and the South American coast this month - classic signs of an El Nino.