January 2008: heat waves & drought
- Rainfall: Extremely low in northern areas from Auckland south, Wairarapa, and the coastal northeast of the South Island
- Temperature: Above average especially Waikato, King Country, Nelson and inland South Island
- Sunshine: Extremely high in the south; well below average in Northland
- Soil moisture: Severe deficits in many North Island areas and the east of the South Island
January was a month of records.
Heat wave conditions occurred across inland areas of the South Island, and even extended to coastal parts of Canterbury and central Marlborough, for the first three weeks of January, with temperatures of 30°C or more recorded regularly. Record daytime maximums for January occurred in inland Otago and inland Southland. January 2008 temperatures were well above average everywhere, with the national average temperature of 18.3°C being 1.3°C above average.
Extremely low rainfall occurred in many areas, with totals of less than 10 mm in the Hauraki Plains, Waikato, King Country, coastal Marlborough and parts of north Canterbury. In Waikato it was the driest January in over 100 years of records. Rainfall was a 25% or less (a quarter) of normal in south Auckland, Waikato, southern Coromandel, King Country, the central North Island, coastal Wairarapa, coastal Marlborough and north Canterbury. As a result severe soil moisture deficits (more than 130 mm) had developed from Auckland to the King Country, South Taranaki, northern Manawatu, Hawke’s Bay to Wairarapa, Wellington, and persisted in the South Island from Marlborough to central Canterbury. There is no single definition of a “drought” but, in general terms, areas with more than 130 mm soil moisture deficit may be said to be experiencing agricultural drought conditions, particularly if these areas are not accustomed to very dry conditions at the time of year.
The only place where rainfall was above average in January was in parts of Horowhenua.
Otago and Southland as well as inland areas of Canterbury basked in their sunniest January on record, whilst well below average sunshine hours were recorded in Northland.
The month’s overall climate pattern was produced by many more anticyclones east of the South Island producing light winds over the southern North Island, and South Island, and easterlies over the rest of the North Island.
Further Highlights
- The lowest air temperature during the month was 0.0 °C recorded at Waiouru. The highest temperature during January 2008 was 34.8 °C recorded at both Timaru Airport on the 12th and Waione on the 22nd.
- From the 30th December to 22nd of January, apart from two days, heat wave conditions occurred in inland and eastern areas of the South Island.
- Wallaceville (Upper Hutt) recorded its highest January temperature on record of 30.9°C (records commenced in 1940) on the 21st and Palmerston North 31.8°C on the 22nd (records commenced in 1918).
- Heavy rain localised to the Kapiti District produced widespread flooding in Horowhenua. Over 200 mm of rain fell at Muhunoa, with 320 mm at Oriwa, 140 mm at Waikanae and 120 mm at Levin in 30 hours.
- The remnants of ex-tropical cyclone Funa crossed the South Island on 22nd January producing 160 mm at Haparapara (Bay of Plenty), 217 mm at Little Devil (Tasman District) and 227 mm at Waiho (Westland). Wind speeds of 158 km/hr occurred at Castlepoint, and 143 km/hr at Mt Kaukau (Wellington) from the westerly quarter. The former was the highest gust for the month.
- Of the five main centres, Auckland was the warmest, Dunedin the sunniest and wettest, and Hamilton by far the driest.
Rainfall
January 2008 rainfall was less than 25 percent (quarter) of normal in south Auckland, Waikato, southern Coromandel, King Country, the central North Island, coastal Wairarapa, coastal Marlborough and north Canterbury. Totals were less than 50 percent (half) of normal throughout Bay of Plenty, Taranaki, northern Manawatu. Hawke’s Bay and the rest of the southern North Island, except Horowhenua where totals were 150% (one and a half) of normal.
Temperature
Mean temperatures were at least 0.5 °C above average in the east of the North Island, and from 1 to 2°C above average over the remainder of New Zealand. Average maximum temperatures were over 2°C above average from the Waikato to the central Plateau, Nelson, and inland areas of the South Island, where some locations were up to 4°C above average.
Sunshine
Sunshine hours were over 150 percent of normal in Southland and Otago, and at least 130 percent of normal in inland areas of the South Island. All these totals were new January records. Above average sunshine hours occurred over most of the remainder of New Zealand. However, cloudy skies prevailed over Northland.
Full report
- Full details of the January 2008 Climate Summary
For further information, please contact:
Dr Jim Salinger – Principal Scientist, Climate NIWA National Climate Centre – Auckland Phone +64 9 375 2053 [email protected]
Dr Jim Renwick – Science Leader NIWA National Climate Centre – Wellington Phone +64 4 386 0343 [email protected]
Acknowledgement of NIWA as the source is required.