It was a blazing hot day in La Quinta, California, and Irving Berlin was inspired to write a song. Not just any old tune: having completed the lyric, the composer told his secretary he “just wrote the best song that anybody’s ever written”.

Though not everyone would agree with his boast, White Christmas went on to become a commercial and cultural success. Made famous by Bing Crosby, who sang it in the film Holiday Inn, it is thought to be the bestselling single of all time, shifting at least 150m copies worldwide.

White Christmas was not a hit initially. But in 1942, two years after it was written, the song topped the US charts, thanks in part to its popularity with American soldiers stationed overseas during the second world war. It was a hit in Britain, too, perhaps helped by the fact that, unlike swathes of the southern US, we actually experience white Christmases – or at least we used to.

The last “proper” white Christmas – at least in southern Britain – with snow settling on the ground, was in 2010, though in the Highlands snow falls every winter. However, as global warming takes hold, soon the only link with white Christmases may be the famous song.