El Nino is a weather pattern that typically creates higher global temperatures.
Scientists predict 2024 will be the hottest on record.
But for now, the cool airflow caused below-average temperatures across most of the North Island and the top and west of the South, Niwa said.
Rainfall for August was below average too, without much in the way of moist northerly air. Over winter, rainfall was also below normal in most places, Niwa said in its Seasonal Climate Summary, also released on Monday.
But the east of the country was the exception, particularly Canterbury in late July.
“During this event, Christchurch, Akaroa, Leeston and Woodend each observed their wettest winter day on record,” Niwa said. The highest single-day recording was 199mm in Akaroa on July 22.
Auckland, which had its wettest month ever earlier this year, saw 282mm fall over winter - only a little more than what fell on January 27.
While it might have felt like the drizzle in Auckland has barely eased since the Anniversary Weekend downpour, the city actually had a below-normal amount of rain over winter.
Other centres experiencing record single-day rainfalls were Rings Beach (Coromandel), Whakamārama (Bay of Plenty), Woodend (Canterbury), Christchurch Airport, Leeston (Canterbury), Akaroa (Canterbury) and Campbell Island.
The warmest main centre over winter was Auckland with a mean temperature of 11.9C, 0.2C above average. Dunedin was the most unseasonably warm, however, 1.2C above average at 8.5C - the warmest winter the southern city has ever experienced.
Purerua, Northland and the South Island’s Westport had their hottest-ever winter maximums - 20.7C in Purerua and 20.3C in Westport.
The highest temperature recorded nationwide was in Whakatu (Hawke’s Bay), which reached 24C on June 2. The lowest was a chilly -10.6C at Otago’s Tara Hills on June 10.
The year 2022 contained New Zealand’s warmest and wettest winter on record.
