Rainfall: Extremely wet in eastern Bay of Plenty, with high rainfall and devastating floods; very dry in eastern Otago with below normal rainfall in many other regions
Temperatures: Below average, and very frosty in Canterbury and Otago;
Sunshine: Above normal in most places with some new July records, cloudier in the far north and east of the North Island
Eastern Bay of Plenty’s rainfall deluge during July was in complete contrast to conditions in much of the South Island and many northern and western North Island regions. While eastern Bay of Plenty had more than 250 mm of rainfall between July 15 and July 18, parts of Marlborough, Canterbury and Otago had throughout the full month less than half their average monthly rainfall. The month was very frosty in parts of Canterbury and Otago, where overnight temperatures were well below average. July was sunnier than normal in most places, below average totals prevailed in the north and east of the North Island. More frequent anticyclones (‘highs’) prevailed in the Tasman Sea and over New Zealand. Northwesterlies were more frequent to the south and easterlies to the north.
Highlights
- The highest July 2004 temperature was 20.5°C, recorded at Nelson Park, Napier on the 29th. The lowest temperature for the month was -9.1°C, recorded at Lake Tekapo on the 23rd.
- Prolonged heavy rainfall occurred in Bay of Plenty, between the 15th and 18th of July resulting in severe flooding, with a state of emergency in the eastern Bay of Plenty. About 2000 people were evacuated from their homes. The flooding was reported to be the worst in the district in living memory. Whakatane Airport recorded rainfall totalling 246 mm in 48-hours and Opotiki 280 mm.
- The North Island’s Desert Road was closed due to heavy snowfall on the 3rd and 4th of July, and several motorists had to be rescued. The Desert Road and Taupo-Napier highway were closed due to further snowfall on the 23rd, with many trucks, and motorists, stranded. Cold southerlies brought further snowfall down to 500 metres in inland high country areas of Canterbury on the 28th.
- Heavy hailstorms occurred in Hokitika on the 5th, and southwest of New Plymouth on the 7th.
- Storm force southerlies occurred, with high seas through Cook Strait on the afternoon of the 22nd, during which time the Aratere endured an 8-hour journey to Wellington.
- Auckland was the sunniest and Dunedin the driest main centre. Rainfall was below average in Auckland, Christchurch, and Dunedin, and above average in Wellington. Temperatures were below average in Wellington, Christchurch, and Dunedin, and near average in Auckland. Sunshine hours were above normal in all four main centres, especially Dunedin.
Rainfall
Rainfall was at least 300 percent of average in eastern Bay of Plenty, and also above average in western Bay of Plenty, Gisborne, and in and around Blenheim. However, below average rainfall occurred in many northern and western North Island regions and throughout the much of the South Island.
Temperatures
The July national average temperature of 7.3°C was 0.6°C below normal. Mean temperatures were below average in most districts, and as much as 1.5°C below average in parts of Buller, Canterbury, and Otago. Overnight minimum temperatures were well below average.
Sunshine
Sunshine totals were above average throughout much of New Zealand, with new July records at Dargaville and Tekapo. However, lower than usual totals occurred in Northland, Gisborne, and Hawke’s Bay.
Full report
Full details of July 2004 summary.
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.