Climate Summary for March 2008

March 2008 another month of summer & drought

• Temperature: Above average especially Waikato, King Country, central and south west North Island
• Soil moisture: Significant deficits in the west of the North Island from Auckland to Manawatu, Wairarapa and Marlborough until end of the month
• Rainfall: Low in Auckland, Waikato, Canterbury and Fiordland
• Sunshine: Above average especially from Taranaki to Wellington, Marlborough and southern New Zealand

March was another month of summer and records.

March 2008 was warmer than December 2007, with temperatures well above average everywhere. The national average temperature of 16.5°C was 0.8°C above average. Heatwave conditions occurred across inland and eastern areas of the South Island from 18^th to 21^st March with temperatures of 30°C or more recorded regularly. Record daytime extreme maximum temperatures for March occurred during this period throughout Canterbury, north and Central Otago. The highest temperature for the year so far of 35°C was recorded at Culverden, Woodbury and Timaru Airport on the 19^th. The highest ever March temperature recorded in New Zealand is 36°C (Ashburton, March 1956).

Severe soil moisture deficits (more than 130 mm) developed again in the Waikato, parts of the King Country, South Taranaki to Manawatu, Wairarapa and central Marlborough until March 29th. Significant soil moisture deficits (more than 110 mm) persisted throughout much of the west of the North Island, and from the Heretaunga Plains to Wairarapa, and in the east of the South Island. There is no single definition of a “drought” but, in general terms, areas with more than 110 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. Rainfalls in the last two days of the month recovered the situation somewhat in Taranaki and Manawatu, and to a lesser extent in the Waikato.

Low rainfall occurred throughout Canterbury, Fiordland, Auckland, Waikato, the King Country and eastern Wairarapa with only a third (30%) to half (50%) of normal rainfall. Rainfall was above average in Wellington, the north of the South Island and eastern Otago. It was generally sunny month, especially in southern New Zealand.

The month’s overall climate pattern was produced by more anticyclones east of New Zealand, with ridges extending back across the country producing light winds over the South Island, and easterlies over the North Island.

Further Highlights

• The lowest air temperature during the month was -1.6 ºC recorded at Lauder on the 10^th. The highest temperature during March 2008 was 34.8 ºC recorded at both Timaru Airport, and 35°C (rounded to the nearest degree) at Culverden and Woodbury on the 19^th. This was 1°C less than the highest ever New Zealand March temperature of 36°C recorded at Ashburton in 1956.
• A tornado funnel was cited in Auckland on 7^th March.
• From the 18^th to 21^st of March heatwave conditions occurred in inland and eastern areas of the South Island.
• The Hamilton area recorded its highest March temperature on record of 29.4°C (records commenced in 1907) on 16^th March, and Palmerston North 31.8°C on the 22^nd (records commenced in 1918).
• The highest wind gust for the month was 152 km/h at Castlepoint on the 11^th in strong westerly conditions.
• Of the five main centres, Auckland was the warmest, Wellington the wettest and sunniest, and Christchurch the driest.

Temperature

Mean temperatures were 1°C above average in the Waikato, western Bay of Plenty, Taranaki to Manawatu and parts of the west of the South Island, and at least 0.5°C above average in much of the remainder of the North Island, Marlborough, Westland, and parts of Canterbury and Otago. Average maximum temperatures were 2°C above average from the Waikato to the central Plateau, Manawatu, South Canterbury and central Otago.

Rainfall

Low rainfall occurred throughout Canterbury, Fiordland, Auckland, Waikato, the King Country and eastern Wairarapa with only a third (30%) to half (50%) of normal rainfall. Below average rainfall occurred throughout much of the rest of the North Island, except Gisborne, the Far North and Wellington. Rainfall was above average in the Far North, Wellington, north of the South Island and eastern Otago.

Sunshine

Above average sunshine hours (at least 110 percent of normal) occurred in many areas of New Zealand. It was particularly sunny in southern New Zealand where totals were at least 120 percent of normal.

Full report

• Full details of the March 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.