Weather Watch: Temperatures soar as summer heat starts to settle in

But tiny jellyfish spoilt a first swim at Takapuna. Photo / Herald on Sunday

Winter is well and truly behind us now as summer heat overtakes the cold and sets in for the months ahead.

In the past eight days we've seen both islands reach the 30C mark for the first time this spring. Officially in the South Island it was Alexandra and Blenheim and in the North Island it was Hastings, but a string of unofficial and reliable weather stations climbed over 30C in other central and eastern areas.

Leighton Thomas told WeatherWatch.co.nz that while the official airport reading in Christchurch said 27C, the temperature hit 30.3C in the Halswell/Hoon Hay area. "First time this season I've hit the magic 30," he said.

The amazing thing about Christchurch is just a slight shift in wind direction can mean the city's temperature fluctuates wildly. On Tuesday it was 28C at 6pm with a nor'wester. At 1pm on Wednesday the wind had shifted slightly to a nor'easter and it was 15C.

Auckland hit 25C on Wednesday, the first time it has recorded a temperature that high since April.

The recent heat has sent Aucklanders to the water, despite a Herald on Sunday story last weekend saying that sea temperatures have still a long way to go before being comfortable.

"I swam at Takapuna Beach at Labour Weekend. It was not cold, as the air temperature was warm - much warmer than in mid May when I stopped swimming last season," Glyn said. "However, it was not that pleasant as there were hundreds of tiny jellyfish everywhere. I did not get stung but it spoiled the pleasure of that first swim. Has anyone else found jellyfish around?"

The heat hasn't spread everywhere. The west coast of the lower North Island has had plenty of cloud and cold winds off the sea. "It was cool and dull here in Kapiti. I did almost think about putting on the heater at one stage, bit of a shock," said Melissa.

The Kapiti and Horowhenua regions have struggled to climb above the mid teens lately.

Meanwhile, humidity, drizzle, cloud and nor'easters affected Northland - classic La Nina weather. Overnight lows in the upper North Island have shifted up a gear - I expect there will be many restless, stuffy, nights this summer over the upper North Island.