12 Jan 2012

2011 a year of weather extremes

6:53 pm on 12 January 2012

Storms, snowfall, floods and tornadoes made 2011 a year of weather extremes.

The National Institute of Water and Atmospheric Research (NIWA) has released its climate summary on Thursday.

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Sub-tropical lows during January produced record-breaking rainfalls while the following month the country melted under exceptional heat for the first half of February.

Winter arrived extremely late; May was the warmest on record, and June was the third warmest experienced.

In contrast, two significant snowfall events affected large areas of the country in late July and again in mid-August when snow fell to unusually low levels across eastern and alpine areas of the South Island, as well as in suburban Wellington.

Numerous low temperature records were broken between 14 to 17 August.

Torrential rain caused a state of emergency to be declared in Nelson on 14 December, following widespread flooding and land slips.

The wettest day recorded was in Takaka, northwest of Nelson, on that date when 392 millimetres of rain fell - nearly the same amount as the entire annual rainfall in Central Otago (395mm).

Despite the record-breaking rain storm, Nelson took the title of sunniest location, recording 2487 hours, followed by Tekapo (2463 hours) and Whakatane (2380 hours).

Of the six main centres, Tauranga was the sunniest (2271 hours) but also the wettest (1698 mm), receiving 40% more rainfall last year than normal.

Christchurch was the driest (621 mm), Auckland the warmest (15.9°C) and Dunedin the coolest (11.4°C).

Timaru recorded the warmest single temperature of 41.3°C on 6 February - a new all-time record in the area since records began there in 1885.

Manapouri had the coldest temperatre, a chilly -10.2°C recorded on 26 July.

NIWA says 2011 was the 17th warmest year since 1909 with an average annual temperature of 12.8°C.