Summer 2007-08

Warm; extremely cloudy and wet in the far north, extremely dry in the Waikato and record sunshine in the south.

• Temperature:Warm, especially in the west, and inland South Island areas
• Rainfall:Below normal in many North Island areas, and the south of the South Island, above normal in Northland
• Soil moisture: Severe in many North Island areas and the east of the South Island in January, persisting in the North Island during February
• Sunshine: Record low values in Northland; record high values in the south

The summer produced some new records. It was a warm summer, with mean summer temperatures were well above average. The national average temperature of 17.3°C was 0.8°C above normal and the highest for summer since 1998/99. January was particularly warm. Summer temperatures were over 1°C above average in Nelson and inland areas of the South Island. Rainfall was below normal over much of the North Island, and in Southland and Otago, with less than 50 percent (half) of normal in the Waikato. By mid summer severe soil moisture deficits had developed in many North Island areas, and the east of the South Island, which persisted in the North Island in February. Above average summer rainfall occurred in Northland, with 200 percent (double) normal around the Bay of Islands. Record high sunshine hours were observed in the southern South Island, whilst record low sunshine hours occurred in the Far North. The overall summer climate pattern was dominated by the strong La Niña conditions, which produced more anticyclones (‘highs’) south east of the South Island, and more frequent mild north easterly winds over New Zealand.

Major highlights

• The highest temperature was recorded in January 2008 with 34.8 ºC recorded at both Timaru Airport on the 12^th and Waione on the 22^nd. The lowest air temperature recorded was -1.7 ºC recorded at Hanmer Forest in December on the 8^th.
• From the 30^th December to 22^nd 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 21^st and Palmerston North 31.8°C on the 22^nd (records commenced in 1918).
• 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. These were all caused by ex-tropical cyclone Funa on 22 January.
• Persistent rainfall occurred in Northland, with almost 200 mm in the Bay of Islands between 1-10 December. Periods of persistent heavy rainfall occurred on the West Coast of the South Island, with as much as 560 mm at Franz Josef between 9-17 December and 258 mm at Milford Sound between 23-30 December.
• In January, 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.
• A subtropical low brought between 200 and 240 mm to the hills between Kaeo and Kaikohe on February 22 and 23^rd, which caused minor flooding in Kaeo.
• Of the five main centres, Auckland was warmest, Christchurch the wettest and sunniest, and Hamilton the driest. Summer temperatures were above average in all five main centres, especially in Hamilton. Rainfall was well above normal in Christchurch, but below normal in the other four, especially in Hamilton. Summer sunshine was well above normal in Dunedin, with the highest total there on record. It was near or below normal in the four other centres.

Temperature

Seasonal mean temperatures were above average throughout much of New Zealand. These were at least 1.0 °C above average in some western North Island areas, Nelson and inland South Island areas. In the east of the North Island and coastal Canterbury these were near average to 0.5°C above average.

Rainfall

Summer rainfall was less than 50 percent (half) of normal in parts of Waikato and less than 75 percent of normal in many other North Island areas, and southern New Zealand. Rainfall was above normal in parts of Northland and Canterbury, with 200 percent (double) normal around the Bay of Islands.

Sunshine

Summer sunshine hours and/or solar radiation were above normal in parts of Northland and Westland, and below normal in South Taranaki, and North Canterbury. Sunshine hours were near normal elsewhere.

Full report

• Summer 2007-08 climate summary (PDF 82 KB)

For further information, please contact:

Dr Jim Salinger – Principal Scientist, Climate
NIWA National Climate Centre – Auckland
Phone +64 9 375 2053
[email protected]

Stuart Burgess – Climatologist
NIWA National Climate Centre – Wellington
Phone +64 4 386 0569
[email protected]

Geoff Baird – Communications Manager
Phone +64 4 386 0543
[email protected]

Acknowledgement of NIWA as the source is required.