STATE OF THE CLIMATE IN 2009

• Highest one-day rainfall: 510 mm,Urunga (New South Wales), 1 April• Highest wind speed (measured): 211km hr -1 , Mandora (Western Australia),21 December2) New Zealand—G. M. GriffithsNew Zealand’s climate for 2009 was characterizedby frequent seesaws in extremetemperature. Heat waves occurred in Januaryand the start of February; May was thecoldest on record; August was the warmestAugust since records began; and October hadits lowest temperatures since 1945. Duringindividual months (notably September andNovember), daily maximum and minimumtemperatures frequently broke long-standing records,with extremely cold temperatures often occurringwithin a week or so of record hot events. The decade2000–09 was the warmest in the instrumental recordfor New Zealand.(i) TemperatureThe New Zealand national average temperature 2for 2009 was 12.42°C, 0.16°C below the 1971–2000normal (Fig. 7.53), consistent with the prevailingsouthwesterlies over the country during the year.Temperatures were generally within 0.5°C of the longtermaverage over most of the country. The exceptionswere parts of Auckland, Waikato, Manawatu, southernHawkes Bay, Wairarapa, Wellington, Marlborough,inland Canterbury, and eastern Otago, whereannual temperatures were 0.5°C–1.0°C below average.The year was notable for two remarkably warmmonths (January and August) and a very warm spellin early February. Heat waves were experienced overthe country 7–12 February, when northwesterliestransported some of the record-breaking Australianheat to New Zealand. Temperatures of 34°C or moreoccurred in many locations on each day in this period.Many new records of extreme high monthlymaximum temperatures were established in January,February, and August. In contrast, New Zealand alsoexperienced four extremely cold months (March, May,June, and October), and an extended frosty periodacross many parts of the country on 16–26 June. Manyrecord-low monthly minimum temperatures were2http://www.niwa.co.nz/news-and-publications/news/all/nz-temperature-rise-clear/seven-station-series-temperaturedataS184 | juNE 2010Fig. 7.53. Annual and decadal mean temperature anomaliesfor New Zealand based upon a seven-station series. Baseperiod: 1971–2000.established in these four months, as well as numerousrecord-low daily minimum temperatures.The decade 2000–09 was the warmest in the instrumentalrecord for New Zealand, with a 10-yearaverage temperature of 12.69°C, 0.11°C above thelong-term normal, just surpassing the previouslywarmest decade (the 1980s).(ii) PrecipitationAnnual rainfall for 2009 was below normal(50%–80% of normal) for parts of Auckland, thecentral North Island, and eastern areas of both islands(northern Hawkes Bay, southern Wairarapa, northCanterbury, inland south Canterbury, and centralOtago). Taupo, in the central North Island, recordedits driest year since records began in 1949 (712 mm).Elsewhere, annual rainfall was near normal.The year 2009 was unusually snowy in New Zealand,with an extended snow season that started inApril and finished in October. Numerous and heavysnowfall events, and the record warmth of August,contributed to a high-risk avalanche season in theSouthern Alps in August and September. Majorsnowfall events to low levels, which were widespread,were observed on 31 May, 16 June, 2–5 July, and 4–6October, resulting in significant community impacts.The exceptionally heavy snow event on 4–5 Octoberaffected Hawkes Bay and the Central North Islandand was estimated to be the worst in October since1967, stranding hundreds of travelers, closing roads,and resulting in heavy lambing losses. Snowfall wasalso observed in Taranaki, Waikato, and Rotorua onthe 6th, for the first time in about 30 years.The most unusual precipitation event of the yearwas a coating of red Australian dust, sometimes 2