New Zealand has experienced its coldest May since 2009, as reported by the National Institute of Water and Atmospheric Research (NIWA). The average nationwide temperature for May 2024 dropped to 9.8°C, significantly influenced by frequent south-westerly winds.
Notable temperature extremes included the coldest point reaching -9.7°C at Cass on May 10, while the warmest was 23.4°C at Whakatu on May 6. The cold snap was widespread, with approximately 35% of weather stations recording temperatures at least 2°C below their average. These conditions were exacerbated by clear skies, light winds, and drier soils, leading to regular frost occurrences, particularly in inland areas.
Both Christchurch and Timaru experienced record low average minimum temperatures for May, chilling to 0.5°C and 0°C respectively. In terms of precipitation, rainfall was generally below normal across most of the South Island and parts of the North Island, although some regions like parts of Auckland and the southern Wairarapa saw significantly more rain than usual.
The weather summary also highlighted extremes in wind and rain, with a top wind gust of 152 km/h at Secretary Island and the highest one-day rainfall of 130mm at Leigh.
Regionally, Auckland emerged as the warmest of the main centers, Tauranga was the sunniest, Dunedin the driest and least sunny, Christchurch the coolest, and Wellington the wettest. Additionally, the sunniest locations for the year included Marlborough and Nelson, leading in sunshine hours.
