Rogue factor causes climate havoc

Last year was one of extremes, with the country suffering everything from heatwave-generated forest fires to some of the worst flooding in living memory.

The year was the coolest since 1993 and one of the wettest on record in parts of the Bay of Plenty, Manawatu, Kapiti, Upper Hutt and Wairarapa.

The National Institute of Water and Atmospheric Research (Niwa) yesterday released its climate summary for 2004.

Principal scientist Jim Salinger said the year had everything from blizzards to heatwaves, which created many records.

"We certainly got the whole range of extremes thrown at us."

Dr Salinger said rogue qualities in the overall climate pattern saw the months switching from one extreme to another.

The year started with high temperatures but before long that heat combined with high winds to produce life-threatening forest fires in Canterbury.

Then, in complete contrast, February brought record rainfall in Taranaki and Wanganui and storms that generated flooding which caused more than $300 million worth of damage in the Manawatu area.

Dr Salinger said June was unseasonably warm - the fifth-warmest since records began in the 1850s. July brought more flooding, this time in the Bay of Plenty.

August brought cold southerlies that produced blizzards and high winds, while persistent cold, stormy southwesterlies dominated the rest of the year.

Last month, plagued by cooler-than-normal sea temperatures, snowfall, mini-tornadoes and hailstorms, was the fifth-coldest on record.

Dr Salinger said there were at least 28 heavy dumpings of rain during the year - 12 of which produced flooding.

High-country regions were affected by snowfalls from autumn to spring, the earliest significant fall occurring in March on the Desert Rd.

There were 19 high-wind events and four damaging hailstorms.

Auckland failed to make any records - unlike 2003 when it was the wettest city in the country - but it did record 2066 hours of sunshine, which is slightly more than normal.

It also had 1331mm of rain and was at least 0.7 degrees cooler than normal in some places.

Of the four main centres, Christchurch was the best place to be last year, with 2096 hours of sunshine and the least rain. Wellington was the wettest.

Dr Salinger said the whole of the country was 0.3 degrees below its average temperature and, while that made last year the coolest since 1993, globally 2004 was actually the fourth-warmest on record.

The cause of New Zealand's cold and wet weather was a series of lows to the east of the country that "got stuck" and brought cold, stormy southeasterlies in February, August and December.

Dr Salinger said the next three months should be cooler than normal and dry in the north and east of the North Island.