Climate Summary for September 2009

Very sunny, with extreme temperature events

  • Sunshine: It was a very sunny start to spring for most of New Zealand.
  • Temperature:  Close to normal in many regions for the month as a whole.  Two extreme temperature events during September: record cold on the 5th and 6th, record warm on the 14th.
  • Rainfall: A dry month in inland regions of the South Island, Coromandel and the Wairarapa. In contrast, wetter conditions prevailed over much of the North Island, in Nelson, coastal Southland and coastal Otago.  Near normal rainfall elsewhere. 

It was a very sunny start to spring.  September sunshine totals were well above normal (above125 percent of normal) in the northern half of the South Island, as well as in the central North Island.  In most other regions, sunshine totals were above normal (between 110 and 125 percent of normal).

Temperatures were close to normal for most regions of the country, for the month as a whole. Exceptions were the northeast of the North Island, and around the Southern Lakes, where temperatures were above average (between 0.5°C and 1.2°C above average).  The national average temperature was 10.6°C (+0.3°C above the long-term September average).   Two extreme temperature events occurred during September, breaking records at many locations; it was extremely cold on the 5th and 6th, and record warm on the 14th.

September was a dry month for inland parts of the South Island.  Rainfall was well below normal (less than 50 percent of usual) in parts of inland Otago, inland Canterbury, Westland and Buller.  Rainfall totals were below normal (between 50 and 80 percent of normal) for parts of Malborough, the Kaikoura coast and inland Southland, but near normal elsewhere in the South Island.   In contrast, wetter conditions prevailed in the North Island, with near normal rainfall (between 80 and 120 percent of normal) in most districts. Above normal rainfalls (between 120 and 150 percent of normal) were recorded in parts of Northland, eastern Bay of Plenty, Hawkes Bay, Taranaki, as well as around Nelson and Oamaru.  Coromandel and the Wairarapa recorded below normal rainfall (between 50 and 80 percent of normal).  

Several notable weather events occurred during September.  Record cold temperatures were experienced on the 5th and 6th, when a large anticyclone became slow moving over the country.  Extreme northwesterly winds affected the southern South Island on the 14th, bringing extreme wind gusts and record-high September temperatures to eastern parts of the South Island.  A deep, wintry, low crossed New Zealand on the 24th, bringing very cold temperatures to many regions, and high winds, snow and ice to some areas.

During September 2009, higher pressures and more frequent northerly winds affected New Zealand overall.

Further Highlights:

  • The highest temperature during September 2009 was 29.0°C recorded at Alexandra on the 14th (a September record). The lowest temperature of -7.2°C was recorded at Hanmer Forest on the 4th.
  • The highest 1-day rainfall total for September was 101.4 mm, recorded at Cape Turnagain on the 24th.
  • The highest wind gust for September was 161 km/hr, recorded at Southwest Cape (Stewart Island) on the 1st.
  • Of the six main centres, Tauranga was the warmest and sunniest, Hamilton the wettest, and Christchurch the coolest and driest. 

Full report

Full details of the PDF File September 2009 Climate Summary

Climate statistics table

Climate statistics for PDF File September 2009

For further information, please contact:

Ms Georgina Griffiths Climate Scientist– NIWA National Climate Centre, Auckland, Tel. (09) 375 4506 (work) or (027) 2936545 (mobile); or

Dr Andrew Tait Climate Scientist – NIWA National Climate Centre, Wellington, Tel. (04) 386 0562 (work) or (027) 327 7948 (mobile)

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