The seaside city of Sochi is actually subtropical, with daily high temperatures around 50 F (10 C), and even though the Alpine events will be held on mountains dozens of miles away from Sochi, organizers are worried that rain and high temperatures will wash out the Games—just as they did in Vancouver during the unseasonably warm winter of 2010. Organizers will do their best to counter the climate with hundreds of snow guns and 710,000 cu m (25.85 million cu ft) of snow stashed from the year before, but Sochi could make for a soggy Games.Among the other worries about the upcoming Winter Games in Sochi—terrorism, empty seats, Shaun White’s new haircut—is something even the czar himself, Russian President Vladimir Putin, can’t control: the weather.

It likely won’t be the last. A report (PDF) from the University of Waterloo in Canada and Management Center Innsbruck in Austria found that only six of the previous 19 Winter Olympic cities will remain cold enough to reliably host the Games by the end of the century should the most dire predictions of global warming come true. Even by mid-century, close to half of the previous host cities would likely be too warm for outdoor sports like Alpine skiing and snowboarding. That includes cities like Squaw Valley in California (1960), Chamonix in France (1924) and Vancouver (2010). “Fewer and fewer traditional winter sports will be able to host an Olympic Winter Games in a warmer world,” said Daniel Scott, the Canada Research Chair in Global Tourism at Waterloo and the lead author of the report, in a statement.

This list is somewhat influenced by the fact that Olympic organizers have been selecting warmer cities for the Winter Games in recent years—with Sochi, by far the warmest city to ever host the Winter Olympics, a prime example. From the 1920s to the 1950s, the average February daily high temperature in host cities was just 32.7 F (0.4 C), a figure that had risen to 46.04 F (7.8 C) between 2000 and 2010. In the earlier years of the Games virtually all events were held outdoors, including ice hockey and figure skating. Today those sports are held indoors, while snow-making machines and refrigerated bobsled tracks have helped organizers adjust to warmer weather for the remaining outdoor sports. But there’s a limit to adaptation—the report’s authors estimate that even under a low emissions scenario, projected average February highs could increase by as much as 3.78 F (2.1 C), and by the 2080s temperatures could increase by as much as 7.9 F (4.4 C) under a high emissions scenario.

Winter Olympians are well aware of the threat that climate change poses to their sports. In April 75 Olympic medallists in skiing and snowboarding sent a letter to President Obama, urging him to take stronger action on climate change. “Without a doubt,” they wrote, “winter is in trouble.” And if climate change is bad as we fear, so are the Games.