Winter 2020 – NZ’s Warmest Winter On Record

File photo.


New Zealand has just experienced its warmest winter on record, according to official NIWA climate data.

NIWA’s Seven Station Temperature Series, which began in 1909, shows the 2020 winter was 1.14C above average, just nudging out winter 2013 from the top spot, which was 1.08C above average.

This year’s result also means seven of the ten warmest winters on record in New Zealand have occurred since the year 2000.

Seventeen locations observed record breaking mean winter temperatures, with an additional 53 locations ranking within their top four warmest winters.

NIWA forecaster Ben Noll says the winter warmth can be attributed to several factors.

“There were more sub-tropical northeasterly winds than normal, particularly in the North Island. This brought warmer air toward New Zealand from the north,” says Ben.

“Sea surface temperatures were above average during winter, especially in August. As an island nation, New Zealand’s air temperatures are strongly influenced by the seas surrounding it.

“Air pressure was higher than normal, particularly to the east. This contributed to a sunnier than normal winter in much of the South Island and lower North Island.

“Climate change – the warmth over winter is consistent with New Zealand’s long-term trend of increasing air temperatures,” says Ben.

The highest recorded winter 2020 temperature was 25.1C on August 30 in Timaru. This was the highest temperature recorded there during winter since records began in 1885 and the equal fourth warmest winter temperature on record for New Zealand as a whole.

The lowest temperature was -12.3°C, observed at Middlemarch on June 14.

Of these locations the most anomalously warm, that is, the one with the largest deviation from average, was Farewell Spit, where mean daily temperatures of 13 degrees Celsius were experienced. This is 2.8 degrees more than the winter average and the warmest on record since records began there in 1971.

Furthermore, mean maximum daytime temperatures at this location were 3.1 degrees warmer than average, while mean minimum, at night-time. temperatures were 2.3 degrees warmer than average. These are also the largest anomalies in their respective categories.

Kaikohe had its second wettest winter on record, with 935mm of rain recorded for the season, which was 187 per cent of normal. Records began in 1956.

At the opposite end of the scale, Reefton had its second driest winter on record with just 291 mm of rain recorded over three months – or 54 per cent of normal. Records began in 1960. Much of the middle and upper South Island observed below or well below normal rainfall totals.

It will come as no surprise that the highest one-day rainfall occurred in Northland in mid-July. Kaikohe and Whangarei received 262 and 251 mm respectively on July 17. This is the highest one day rainfall amount observed for both locations during winter. Kaikohe records began in 1956 and Whangarei in 1943.

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1 Comment

Yup I can agree....

Posted on 05-09-2020 18:56 | By groutby

....that we have had a very ’mild’ winter, and as for the future..well who really knows, we must be prepared for the naturally occuring change in climate that is before us, and because it is not reversible, make plans for continual and positive changes...

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