Patrick Malley under his pruned and dormant kiwifruit vines that will struggle in mild winter as the crop needs cold weather to grow properly. Photo / Michael Cunningham
From drought to deluge - and now Northland is feeling warmer than the normal winter chill, thanks to a combination of northeasterly winds, warm ocean temperatures and the La Nina effect.
The "mild winter" is helping crops such as avocados mature earlier than expected and attracting out oftowners to the region, including those who have holiday homes in the mid and Far North.
Niwa meteorologist Ben Noll said temperatures in Northland so far this winter have been between 1C and 2C above average which explained why people were not feeling as cold as they usually would between June and August.
With the mercury hitting 22.7C on July 3, Kerikeri recorded its warmest July since records began in 1945 and has the fourth warmest overnight temperatures for this month.
The average overnight of 8.3C is 1.2C above average at this time of the year.
"That shows it's been a pretty mild winter in Northland and a good portion of that boils down to the wind direction. In June, there had been more northeasterlies than normal and that has generally continued into July," Noll said.
He said another reason was ocean temperatures which had been 0.5C above average in June in the upper North Island.
"More high pressure overall kept those southerly fronts at bay. Northland has dealt with flooding and, as you move forward in the next couple of weeks, La Nina can bring warm and wet weather in the eastern parts of the North Island."
During a La Nina event, ocean water from off the coast of South America to the central tropical Pacific cools to below average — a result of stronger than normal easterly trade winds, which churns cooler, deeper seawater up to the ocean's surface.
This unusually cool water in the eastern Pacific then suppresses cloud, rain and thunderstorms, as sea temperatures in the far west of the ocean warm to above average temperatures.
The last La Nina in 2017-18 came with a freak marine heatwave that set the stage for New Zealand's hottest summer on record.
"For the rest of winter and into spring, expect the same mild winter weather to continue with cold days here and there. It's certainly going to be wetter in the upcoming three months in Northland than what you saw early this year," Noll said.
Kerikeri Business Association chairman Jason Vokes said out-of-towners who owned holiday homes have driven up during weekends this winter to enjoy the winterless north.
"The Taiwanese cherry which is a noxious weed is flowering at the moment but I recall it happening later, around spring. The avocado crop is getting ready two to four weeks earlier. It does feel like winterless north this winter," he said.
Fruit grower Patrick Malley, co-owner of Maungatapere Berries, said a mild winter generally meant some crops like raspberries and blueberries benefited and came out in spring earlier but a majority of crops got confused. Kiwifruit, for example, struggled with warm weather, he said.
"A good winter enables the bud to come out quite synchronous, close to each other. This time, because it's warm, they would be very sporadic and the warmer than usual weather would have a significant effect come harvest," he said.
Malley said it was critical for kiwifruit growers to have a good application of dormancy sprays this winter to try to mitigate the effects of the warm weather.
Avocado grower John Dawson, of Mangawhai, said avocados grown in the Far North and the Bay of Plenty were further advanced in terms of maturity compared with those in places such as Whangarei and Kerikeri.
However, he said his crops were running a month behind due to the drought in summer months.
A former Northlander living in Tauranga, Doug Delaney, spent nearly a week visiting family and friends around Northland and said the region was consistently warmer in the early mornings and as the day progressed.
"It's been wet when we were there but it's certainly been a lot warmer than I'd expect in a normal winter. I wonder whether global warming is having an impact."