It is not the only thing about him which is ever-so-slightly larger than life. The British have always poked fun at themselves for talking so incessantly about the weather. It was probably only a matter of time before a breed which began life standing woodenly guard over a baffling display of cold fronts and arrows, joined the select group of TV `personalities' nowadays more likely to be seen in the pages of Hello than in Radio Times.
Ian, whose OU degree - mainly geography and geology studies - played a part in his metamorphosis from geography teacher to TV and newspaper weatherman, author and all-round media pundit, has his own theory about the rise and rise of the forecasters' star:
"The climate has always been changeable but the weather is conspiring to get itself into the news more. In the last 20 years there has been some extreme weather and warming-up, so we are seeing a lot more on the TV and in the media."
Indeed it was one of the most memorable examples of extreme weather getting itself into the news which was the turning point in Ian's weatherman career.
In the wake of public disbelief and fascination over The Great Storm of 1987, he was invited by an editor he'd met through his weekly newspaper forecasts, to collaborate on a coffee table hardback, Surrey In The Hurricane, a record in words and pictures of the scenes of flattened trees and caravan parks, lucky escapes, and individual heroism which people who experienced the storm will want to rehearse one day to their grandchildren.
Ian has his own particular memories of an event which, in contrast to the unfortunate Michael Fish, confirmed his forecasting credentials. He recalls how two days ahead of the weekly paper's appearance he had a call from the Editor querying whether his forecast of a `furious storm on the way' was reliable. When Ian confirmed that the weather was definitely going to get worse the Editor said he was going to run the forecast as a major news story, warning readers of the fury to come.
"By early Thursday evening the paper was on the streets and the Editor phoned me to say `We've got egg on our faces'. I assured him things were going to be stormy. The temperature had gone up from 9 degrees to 16 - a very dramatic increase that said amazing things were happening.
"Next day he phoned again in paroxysms of pleasure. There was mayhem everywhere - but he was delighted and said `We've scooped everyone'. This bitter sweet success earned him a place on ITV's tenth anniversary round- up of the storm, but like any forecaster Ian has fallen victim to the occasional whims of the British weather.
"You can't be right all the time. One of the worst times for forecasting is in the spring when the weather can be fickle because the land is beginning to heat up, but it's still very cold in the arctic and the seas are cold so you get incredible variability," he explains.
It's from this contrast that the old weather saying `he who bathes in May may soon be laid in clay' originates.
Ian is an avid collector of such sayings and has recently brought them together into another book Red Sky at Night, which aims to sort the meat from the myths and, on the way, proves how much serious science lies behind many of these inherited verses. (He dismisses rain on St Swithin's Day as the herald of 40 days rain to follow as `rubbish'.)
However this collection, together with a programme of talks to local schools and clubs, plus a bursting shelf of other publications he has authored or contributed to - The Surrey Weather Book, London's Hurricane, Frosts, Freezes and Fairs, The Dorset Weather Book... and more - have developed from Ian's belief that if he can make sense of isobars and atmospheric conditions by mixing meteorology with personal accounts, anecdotes and good photographs then the public appetite for reading as well as talking about the weather is boundless.
He credits the OU with helping him develop the organisational skills and self-motivation to build a career out of this mix of forecasting, writing, commentary and publishing.
Taking this a step further, Ian recently launched his own weather magazine aimed at the general reader. Weather Eye is published by Ian's own company, Frosted Earth, whose name was chosen `as an antidote to global warming', Ian says. The magazine provides some useful insights into making sense of the skies. We all have the capacity to read the weather far more than we give ourselves credit for, he says.
He concludes: "At the latter end of the twentieth century we were thinking we were becoming immune to the power of nature. These extreme weather events are a reminder of our vulnerability."
Frosted Earth, 77 Rickman Hill, Coulsdon, Surrey CR5 3DT. Telephone: 01737 554869.Reuse content