Some people say his science is bogus, but plenty of people swear by "Moon Man" Ken Ring's weather predictions.
If they didn't, he wouldn't put out a new book every year.
His 2013 almanac has just hit the shelves, full of detailed forecasts for each day about where the wind will be coming from and whether or not it's going to rain.
For instance, on Good Friday, Mr Ring predicts: "Fine in the north and east of the North Island. Some showers elsewhere. Over the South Island, shower or rain in the south and west. Fine in Marlborough and Canterbury."
Incidentally, the moon will be full on that day.
Mr Ring bases all his predictions around what the moon is doing.
He points out in a disclaimer at the start of the book that his forecasts are only "best-endeavour opinions".
"No guarantee of 100% accuracy is claimed. Sciences that depend on nature's patterns are never exact despite best intentions," Mr Ring says.
When he is wrong, however, he is known to still claim accuracy.
Otago University PhD student David Winter gives an example from a couple of years ago: "His prediction for 100mm of rain in New South Wales was accurate, it's just that it arrived further west, two dates later, and was only 20mm."
It is a bit like the football commentator on The Simpsons, "Smooth" Jimmy Apollo, who proudly claims to be right "52% of the time!"
Except Mr Ring reckons he's right between 80% and 90% of the time.
The only way to find out is to get the book and see first hand.
Without giving too much away, Mr Ring predicts this summer will be drier than normal for most of the country.
Helpfully, he also gives people a useful heads-up for rough or inconvenient weather during the year.
In May 7, for example, the last place you want to be trying to fly in or out of is Hamilton, due to fog.
Although, being Hamilton, there will probably be fog on every other day of the month as well.
Similarly, on June 2 Mr Ring predicts "chance of unusually low temperature in Omarama".
Predictions for the wettest or driest areas, it should be noted, are often preceded by a "may be".
The book is billed as "essential" for fishermen, farmers, skiers, gardeners and all Kiwis.
Whether or not it is accurate will probably be in the eye of the beholder – people who are convinced of his method will find a way for it to be correct.
Others will be content to simply poke their heads out the window.
But for those who want a long term forecast, and don't mind the odd wayward "prediction", this book will surely be compelling reading.
Ken Ring's New Zealand Weather Almanac 2013 is available now, published by Random House.