The pastime of cloudspotting now has an appreciation society, a website and even its own handbook, which is on the way to becoming a bestseller, with sales of 20,000 copies in the past month.

The phenomenon was started as a joke, but has spawned a mass following by tapping into deep-seated elements in Britain’s national character: the fondness for collecting and list-making, and an endless fascination with the weather.

Gavin Pretor-Pinney, author of The Cloudspotter’s Guide, said he launched the movement unintentionally. “I was at a literary festival in Cornwall last year. A friend of mine asked me to do a talk on clouds, and I agreed. But I was scared that only two or three people would turn up, so just to give it an importance I called the speech ‘The Inaugural Lecture of the Cloud Appreciation Society’.

“When I did the speech, the whole venue was packed, and people were coming up to me afterwards asking if they could become members.”

He created a website which soon attracted millions of hits each month, and the book is to be published in America in June, with plans to translate it into German and Japanese. The society has more than 2,500 members in Britain, and a further 500 in another 35 countries.

His book draws on meteorology and mythology, but owes a debt to Luke Howard, a 19th-century Quaker businessman whose 1802 work, On the Modifications of Clouds, gave clouds the names that are still in use today.

Pretor-Pinney has a theory about the rush to gaze heavenwards at “the ultimate art gallery above”. He points out that clouds are the most “egalitarian of all of nature’s works” — and unlike stargazing, disrupted by Britain’s urban glow at night, there are no man-made obstacles to viewing them.

He admits, however, to a more prosaic explanation. Cloudspotting in Britain might be so popular because the skies are so often covered by them that people have decided to make a virtue of Britain’s changeable weather. “We think blue sky is boring,” he said.

Cloudspotters vary in the degree of engagement with their hobby. Pretor-Pinney plans to pursue tornado clouds in the tornado belt of America, potentially risking his life, while others scan the sky looking for enlightenment.

On the website, some enthusiasts argue that clouds should be watched to a musical soundtrack. One member writes: “Try watching clouds to Bach or panpipes or Coldplay or Keith Jarrett or choral music or Debussy . . . it might just extend your life experience.”

Others in the cloudspotting movement are motivated instead by the urge to tick off a list. Spotters notch up their triumphs by taking a picture before it blows away or dissolves into thin air.

Spotters see famous faces where others see only the prospect of rain. One of the most popular pages of the website carries images of clouds that are said to resemble an elephant, UFOs, and even Albert Einstein.

Cloudspotters — who prefer the formal name nephologists, or the informal “nimbomaniacs”, even have a name for seeing objects in clouds. “It is called pareidolia — finding meaningful shapes in meaningless objects,” said one American member of the society.

A highlight of the British spotting season is the search for noctilucent clouds, which float at the edge of the Earth’s atmosphere at about 50 miles above ground. One group will hope to catch a glimpse of them next month in the north of Scotland — they are visible at night because they fly so high that the sun’s rays can still hit them.

However, the serious spotters dream of seeing Morning Glory, which can only be found hovering at about 2,000ft above the Gulf Savannah in the Australian outback during the spring months of September and October.

The cloud looks like a tube that is 600 miles long, and travels at 35mph. It is popular with glider pilots, who travel from all over Australia to go “cloud-surfing” on it.

Explore UK News

• Crime News

• Education News

• Health News

• Science News

• Scotland News

Times Recommends

• Looking for romance on the Blairs' love bus
• Children 'immersed in culture of violence'
• Hunt for black gold sweeps the country