Northland is showing signs parts of the region will replicate past trends and head into severely dry conditions after the warmest winter on record.
Winter this year was the warmest on record throughout New Zealand with temperatures above 0.51C to 1.20C above average, surpassing last year's record.
According to Niwa, pockets of 1.20C above average were recorded in Northland, Waikato, Wairarapa, Nelson, Tasman, West Coast, Canterbury and Otago. No areas had below average temperatures.
Dargaville stood out, recording -4.1C on June 24— the second lowest record or near-record daily minimum air temperature since records there began in 1943.
The temperature dipped to -4.1C briefly about 8am. In comparison, Whangārei recorded 1.8C, Kerikeri 2C, and Kaitaia 4.8C on the same day.
Dargaville's lowest daily minimum temperature on record was -4.4C on two days in 1957 — July 13 and July 30.
Dargaville recorded its fourth highest winter wind gust of 102 km/h on June 29 since records began in 1997.
Parts of Northland have had above normal rainfall except on the west coast where 50 per cent to 79 per cent below normal rain fell in winter.
Niwa climate scientist Ben Noll said below normal rain in parts of Northland was one of the signs the region would experience dry spells this year.
"There's no immediate pressing concerns at the moment but there are signs the region will go to drier conditions around October/November, as was the case in the last one or two years," he said.
Noll said the -4.1C recorded in Dargaville could have been as a result of low soil moisture levels that allowed radiation cooling at night.
Ruawai dairy farmer Garth Preston said although the below average rain in winter followed a drought, there has been good grass growth with decent rainfall in August and so far this month.
"Because we have clay soil, conditions for grass growth have been good and there's been phenomenal growth in winter and spring. A lot of that is what is called compensatory growth.
"Farmers in Ruawai have had too much grass growth. There wasn't much moisture in the ground early on but around late May, June through to August it's been amazing- out of this world."
Preston said good quality silage stocks would put farmers in good stead heading into warmer, drier months.
He didn't feel temperatures dipping to sub zero in his area during winter but said any frost would have gone early.
Dargaville recorded its fourth highest winter wind gust of 102 km/h on June 29 and the second lowest daily maximum temperature of 8.9C on June 23.
Second highest mean air temperatures in winter were recorded in Cape Reinga (13.6C), Kaitaia (13.6C), Kerikeri (12.9C), and Whangārei 13.1C (second highest).
Highest mean minimum air temperature since 1948 was in Kaitaia (10.6C) and second highest in Kerikeri (8.6C)
Whangārei had the highest mean maximum temperature of 17.4C— 1.5C departure from normal— and Kerikeri fourth highest at 17C.
Several factors contributed to the record warmer winter, including frequent high pressure over and east of New Zealand, warm northerly-quarter wind flows, warmer than average coastal waters, and the influence of a decaying La Nina early in the season, followed by a trend back toward La Nina late in the season.