Early spring already here

The days are getting longer and the weather warmer but it may be a bit early to start dusting off the barbecue, says a weather analyst.

Weatherwatch head analyst Phillip Duncan says the sun is rising earlier across New Zealand and many places are already experiencing spring-like conditions during what is normally the coldest part of the year.

Since the shortest day (June 21) the South Island and lower North Island have gained over an hour of daylight.

Aucklanders are now seeing an extra 50 minutes of daylight while Dunedinites have 73 minutes more.

Mr Duncan says the days will lengthen more quickly as the spring equinox approaches in late September - which is when many celebrate the astronomical start of spring.

While it may still be too early to don a T-shirt and enjoy a barbecue and cold one on the deck after work, spring is already here, he says.

"This was based on a lot of evidence that was pointing towards a very, very early start to spring and no signs of a winter comeback within the coldest part of the year which is up until the middle of August.

"There are some colder changes coming up and maybe some snow on the South Island ranges but nothing that indicates anything major on a nationwide basis ... it was a very, very short winter."

Mr Duncan says it has been warmer and drier across much of New Zealand thanks mainly to high atmospheric pressure around the upper North Island and Tasman Sea.

Temperatures in Auckland and the north have hovered around the 18-degree mark while overnight lows are a relatively balmy 12 C.

"But we can still get a southerly. We might even get a snowstorm in the South Island before the year is done but the chances of a frost being really severe is looking less likely. But there is still a moderately high chance of frost in September."

Niwa principal scientist Dr Andrew Tait said July was "particularly warm" in the central North Island from Taupo south while many parts of the South Island had average temperatures 2C warmer than usual.

He said the first seven days of August had been about two degrees warmer than usual for most of the North Island.

"When you start getting two degrees or more above then it's kind of like you're in the next month.

"There are a lot of people talking about how there are very early spring-like conditions and that's pretty true to form."

Daylight hours

Auckland: Now sees an extra 50 minutes of sunlight compared with the shortest day of the year
Wellington: An extra 61 minutes of daylight.
Christchurch: An extra 67 minutes of daylight.
Dunedin: An extra 73 minutes of daylight.
Source: weatherwatch.co.nz

Sunrise/sunset

In Auckland:
June 20: 7.33am/ 5.12pm
August 9: 7.12am/ 5.41pm

In Dunedin:
June 20: 8.20am/ 4.59pm
August 9: 7.47am/ 5.40pm
Source: Royal Astronomical Society of New Zealand rasnz.org.nz