Record-breaking low temperatures were measured by meteorological stations across New Zealand last week, following the outburst of cold weather conditions across the country.
NIWA office reported record low temperatures have been measured in Kaitaia, Kerikeri, Warkworth, Cape Reinga, Port Taharoa in Waikato, Waione in Hawke's Bay and Ngawi in Wairarapa.
On Saturday, July 11, Kaitaia measured 0ºC (32ºF), while -0.7ºC (30.7ºF) was measured in Kerikeri and -2.3ºC (27.8ºF) in Warkworth on Sunday, July 12.
The coldest July temperature, of -4.9ºC (23.1ºF), since 1959, was measured in Te Kuiti, Sunday, July 12. The coldest July temperature, of -2.6ºC (27.3ºF), on record since 1947, was measured in Greymouth on July 9.
A cold southerly, bringing ice cold showers and snow, followed by a high pressure system, unable to trap heat, caused this outburst of cold weather, according to Niwa climate scientist Gregor Macara: "Clouds act like a blanket at night and traps heat over the Earth's surface, whereas clear skies enable enhanced night-time cooling as this heat escapes the atmosphere. This process has contributed to the severe frosts observed lately".
Featured image: Mt Ruapehu and surrounding farmland covered in snow, July 2015. Image credit: Susan Pepperell, NIWA.