Take this as a weather warning - from summer through to the end of winter, 2010 is going to be a miserable year.

Ken Ring, a long-term forecaster with unorthodox methods but a surprisingly accurate track record, has predicted next year's weather to be "disappointing", with wet and cooler summer months, followed by a winter that lasts a month longer than this year, with record-breaking cold snaps.

The summer will be rainy, Canterbury could be as low as five degrees by February, and March and April could see the coldest months on record for half a century.

Christchurch can expect its heaviest snowfall since 1945, Wellington will face gale force winds, and thousands of shorn sheep in the Hawke's Bay and Manawatu may die from the cold.

It's also likely next year's ski season will see the last decent powder for five years - although chances are it will run through until January 2011.

Ring's methods of using the moon and tides to forecast well beyond the timelines of MetService or NIWA have raised eyebrows in the scientific community for years, but the Kiwi weather watcher has been largely on the mark in New Zealand and overseas.

In 2008, he predicted the Shotover River in Queenstown would freeze over in July and that we would experience colder than average winter months - both predictions rang true.

Even the Irish are applauding him for accurately predicting the country's mini-heatwave in June and the wettest July on record, completely contradicting the UK Met Office which said it would be a "barbecue summer".

His weather predictions are laid out in the latest Ken Ring's Predict Weather Almanac 2010, to be released this Friday.

Ring's working principle is that weather recycles just as tides do, and predicting the tides means he can logically forecast, based on the moon's "gravitational forces" going through the air to get to the ocean.

His methods derive from studying the fishing calendar on the East Coast, where local Maori would use the tides and moon cycles to predict the weather. "It sounds complicated but it's really just about the moon and the tides," said Ring.

"Based on feedback I'd say my predictions are about 85 per cent accurate, and that's feedback from my peers - farmers, fishermen and trampers - people that know the outdoors and how these cycles work."

Despite a huge following, Weather Watch analyst Phil Duncan is sceptical about Ring's theories, saying it is too difficult to predict weather more than a month out.

He admits there is a science behind Ring's methods, and agrees that summer could be cooler than average.

"We're seeing the makings of an El Nino on the way, which is not confirmed yet, and it could mean Auckland could be cooler and places like Waikato and Wellington will have stronger westerlies," he said.

"I'm a big believer in short-term forecasting, but I wouldn't do anything more than a month out. I don't think anyone can predict what can happen in a year's time."

MetService weather ambassador Bob McDavitt said he would not comment on anyone else's theories, but could say MetService - which conducts its seasonal outlook with the help of Niwa - has recorded sea surface temperatures that predict El Nino weather patterns. "These temperatures can change from month to month, so I couldn't comment on anything more than that," he said.