By day, Iain Cameron is a health and safety manager for an aerospace company in Edinburgh, Scotland. But by night—or, at least, on weekends and holidays—he is one of Great Britain’s most tenacious “snow patchers,” people who seek and document the island’s patches of snow, the ones that manage to hold on through the warmer months, through quirks of topography, shadow, and microclimate. These are the closest Britain comes to having its very own glaciers. Some patches are fleeting and variable, while others can last the whole summer. Of these, the Sphinx, in Garbh Choire Mor on Braeriach in the Cairngorms, is one of the oldest and heartiest.

But this year is different. Crucially, the winter of 2016 was warm and dry, with little snow, and the following spring similarly mild. In an ordinary year, there might be as many as 100 patches left by September. In 2016 there were 82; in 2015, a staggering 678. This year, there are two. For the first time in 11 years, Ben Nevis, Scotland’s highest mountain, is snowless. The Sphinx has hung on, for now, but its days are numbered.

Cameron has been watching the Sphinx closely, and determined that it will melt and sublimate entirely by September 20. This, according to the Financial Times, will be likely the first time in more than ten years, and likely the sixth time in three centuries, that all of Great Britain will be without snow. When the Sphinx does go, however, Cameron hopes to be there, with his tent and his cell phone. “It may go at 3 am on a wet Wednesday night but this has never been chronicled before,” he told the newspaper. “So to be there would be amazing.”

Cameron has been fascinated with summertime snow since childhood, he told The Guardian. He climbs not for peaks, but for the patches, which “tend to sit in the little gullies and corries below the peaks. I go straight to the snow.” From these expeditions, he writes an annual report on snow and its patches for the Met Office, the United Kingdom’s weather agency, and maintains a social media presence on Facebook and Twitter. Snow fans are waiting with bated breath for his updates on the Sphinx. Paul Sutherland, a fan, summed it up in a comment: “The whole country is watching …”