Sunshine hints at warm spring

Neko Beard-Bot, 3, joins in as Auckland's Wynyard Quarter celebrated its fourth birthday yesterday. Photo / Doug Sherring

The days are longer, the mercury is rising — that only means one thing.

Warmer weather and longer days are on the way - but we're not out of the winter woods just yet.

Hints of spring will arrive this week with warmer temperatures spreading across the country, according to WeatherWatch head analyst Philip Duncan. Temperatures are forecast to be a mild 19C in Whangarei and Napier today and tomorrow, well above the August average. The mercury will hit 17C today in Auckland and Tauranga. Highs will be a few degrees lower in the South Island.

"If I was a betting man, I would be betting we are past the coldest part of winter," Duncan said. "We are getting a real mixture now of warm days and cold days. The spring pattern normally kicks off in August and September and it will be warmer in some regions earlier this year."

He said eastern areas of New Zealand had a better chance of seeing the sun, but the west may still be plagued by rain. Northern areas should remain dry, but frosts were still a possibility.

"People always ask me, 'are we past the coldest part of winter?' and my general feeling is 'yes' but that doesn't mean we might not get a cold snap this month."

MetService forecaster Emma Blades said although temperatures should rise next week, we should brace for a return of cooler southerly winds in the second week of August. "We musn't be fooled by warmer weather," she said.

"It will be a fairly typical August with intermittent westerly winds and intermittent rain."

Blades said the El Nino weather pattern was to blame for the southerly outbreaks over winter and had upset the normal balance of trade winds in the Pacific.

Average highs for August should hit about 15C and nudge up to 17C next month.

The National Institute of Water and Atmosphere warned on Friday that an El Nino summer was "extremely likely". The system typically brings cooler, wetter conditions, including higher rainfall to regions that are normally wet, and often drought to areas that are usually dry.

But on the bright side, longer days and shorter nights are finally here. "Each night that passes is getting about two or three minutes shorter or, put another way, about 15-20 minutes brighter a week," said Duncan.

"Those in the lower South Island are seeing the biggest difference, with almost an hour of extra daylight compared to the shortest day.

"Northern New Zealand has well over half an hour of extra sunlight today compared to six weeks ago.

"The days get longer, fastest, in September as we rush towards the equinox on September 23. After that the days become longer than the nights."