Mt Cook dips to -11.6C, lowest temperature this year
It was a chilly -11.6C in Mt Cook Airport on Saturday night – the coldest temperature recorded this year by MetService.
That’s just a tad colder than the -11C recorded by MetService Ō at a station near mārama on June 22, and the -11.2C recorded by Niwa Weather at Middlemarch on June 23.
Canterbury residents also woke to an icy morning yesterday. Christchurch Airport dropped to -5.5C between 5am and 6am, the coldest temperature at that station in 2022, and the eighth-coldest among the stations used by MetService overnight.
At Mt Cook, the temperature dropped between 11pm and midnight on Saturday, but then increased significantly by 1am yesterday, as strong northwesterlies came through, MetService meteorologist Tui McInnes said.
The lowest temperature between midnight and 1am was -10.2C, but for the 10 minutes from 12.50am and 1am, the average temperature was 3.1C.
‘‘It’s quite a big difference,’’ and happened quickly, McInnes said.
The main reason the airport was so cold was because it was completely snowed in.
‘‘The coldest temperatures happen in the days after it snows. The snow acts like a big mirror to the Sun’s radiation,’’ McInnes said.
Much of the heat in the atmosphere was created by the land absorbing solar radiation and then re-emitting it at a different wavelength.
‘‘When it’s snowing you don’t get anywhere near the same level of absorption.’’
Other cold temperatures recorded overnight on Saturday were -7.7C at Tekapo, - 8.4C at Pukaki Airport and -9.1C at Burkes Pass.
In Christchurch, the cold temperature was largely the result of mostly clear skies and little wind, McInnes said.