Climate Summary for January 2010

Wet and cloudy for much of the country.

  •     Rainfall: Exceptionally wet in the east of the North Island and parts of the Waikato following heavy rainfall on the 31st.  Above normal rainfall for most other regions of New Zealand – the notable exceptions being Northland and parts of coastal Canterbury and north Otago, which recorded well below normal rainfall.     
  •     Soil moisture:  Severe soil moisture deficits continue in Northland.  
  •     Temperature:  Near average temperatures across much of the country. Small pockets of below average temperatures in Manuwatu-Wanganui, Wairarapa and southern Hawkes Bay, south Canterbury and in the Clutha.
  •     Sunshine: Extremely cloudy over the lower North Island, and eastern South Island.  Very sunny in Northland.  

Overall, January 2010 was an unsettled month, being wet, slightly cool, and extremely cloudy.  The month was characterised by lower pressures than normal over the country.

The most significant extreme weather event to impact on the country in January was the heavy rainfall event on January 31st, which affected the eastern and central North Island, as well as Waikato and Coromandel. A moist, easterly air stream brought heavy rain and embedded thunderstorms to these areas, causing flooding, slips, and road closures. Particularly hard hit were Gisborne and Hawkes Bay.  This one event produced most of the month’s rainfall total in these regions. More than double normal January rainfall was recorded in Gisborne, Hawkes Bay, the Wairarapa and in parts of the Waikato.  Above normal rainfall (between 120 and 150 percent of normal) was also recorded in most other regions of New Zealand.  The notable exception was Northland, which experienced well below normal rainfall (less than 50 percent of January normal) with severe soil moisture deficits continuing through to the end of January.  Other areas which experienced below normal rainfall (between 50 and 70 percent of January normal) were coastal Canterbury and north Otago.

Overall, January temperatures were near average (between -0.5°C and 0.5°C of average) across most of New Zealand.  The exceptions were small pockets of below average temperatures (between 1.2°C and 0.5°C below average) in Manawatu-Wanganui, the Wairarapa and southern Hawkes Bay, south Canterbury and in the Clutha district. The New Zealand national average temperature for January was 16.7°C (0.4°C below the long-term January average).

January sunshine totals were well below normal (below 75 percent of normal) over the lower North Island, and the entire eastern South Island, from Blenheim to Dunedin.  In contrast, Northland experienced a very sunny month, with sunshine totals between 110 and 125 percent of normal.  Elsewhere, sunshine totals were close to normal.  

Further Highlights:

  •     The highest temperature was 34.3°C recorded at Blenheim on the 1st (not a January record). The lowest temperature of -0.3 °C was recorded at Alfredton on the 24th (not a record for January).
  •     The highest 1-day rainfall was 202.6 mm, recorded at Franz Josef on the 6th (not a January record).
  •     The highest wind gust was 165 km/hr, recorded at Stewart Island on the 1st (not a record for January).
  •     Of the six main centres, Tauranga was the warmest and sunniest, Hamilton the wettest, Dunedin the coolest, and Christchurch the driest.

Full Report

Full details of the PDF FileJanuary 2010 Climate Summary

Climate statistics table

Climate statistics for PDF File January 2010

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)