They took their horses to the Swiss Alps for snow polo. Instead they got Slush.

The horses were all ready. The players were ready. So did the spectators, many of whom had arrived in the idyllic winter wonderland of St. Moritz, Switzerland, in soft fur coats and stylish moon boots. Everything was there for the Snow Polo World Cup.

But the weather didn't cooperate.

The high temperatures made the frozen Lake St. Moritz too muddy and slippery for the horses to gallop. As a result, event founder Reto Gaudenzi canceled all matches for the 39th installment of the tournament, which was held from Friday to Sunday, and instead resorted to three days of slower, more stationary penalty shootouts .

The event, which involves playing a variation of polo on packed snow atop the frozen lake surface, draws thousands of people to St. Moritz, a luxury ski resort, many from the upper echelons of the 1 percent. Sponsored by companies selling private jets, exclusive retreats and top-shelf champagne, it included a gala dinner described by organizers as “the hottest ticket in town.”

Organizers tried to keep an optimistic tone: “With the weather gods being cheerful and perhaps having brought too much sunshine to St. Moritz lately, the ice depth is good and completely safe,” they said in a statement. (While there was no risk of anyone falling Through the ice raised concerns about horses falling on the ice.)

Temperatures have been well below freezing in recent weeks, but the week before the tournament they hovered as high as 50 degrees Fahrenheit during the day. Overnight, temperatures dropped below freezing again, but not long enough to prevent puddles from forming on the frozen lake.

These temperatures were unusually high, if not unheard of, for St. Moritz, which is about 6,000 feet above sea level.

“This is very mild for the mountain areas,” said Lionel Peyraud, forecaster at the Swiss weather service MeteoSwiss. “The air is really quite warm.”

The snow polo tournament still attracted about 25,000 visitors over three days, organizers said, many wandering around the lake to eat, listen to music and drink champagne despite the limited competition.

“It's the place to be,” said Markus Berger, a spokesman for Switzerland Tourism, adding that part of the reason for attending was to “see and be seen.”

“For many of them, it's kind of like a class reunion,” Mr. Berger said.

The end of January is the high season for winter tourism in the Swiss Alps. At Engadin's small airport, which can accommodate private jets, about 25 planes landed and took off every day this weekend, said Christian Gorfer, the airport's chief financial officer and a native of the region.

“It's crazy right now,” Mr. Gorfer said. “As an airport we must look at the balance between movement and the environment.”

The tourism sector in Switzerland, which is highly dependent on the winter holiday season, is well aware of climate change. Communities at lower altitudes in particular have tried in recent years to find other sources of income by attracting people for activities other than skiing.

But St. Moritz is so high up that the effects of climate change have not yet been felt so intensely, Mr. Berger said.

“I don't know how the situation in St. Moritz will develop, whether this is an exception or whether this will become a new norm,” he said.

Although the Snow Polo World Cup in Switzerland does not typically receive much media attention, the event's problems were still meaningful to the rest of the country, Mr. Berger said, because it was all part of “the image of the Swiss.” winter.”

This weekend the next event on the frozen Lake St. Moritz is scheduled: the White Turf horse race. Thousands of people attend the event, which is more than a century old and is held on three Sundays in February every year. But the White Turf could face the same problems that plagued the Snow Polo World Cup: Temperatures are expected to remain around 40 degrees Fahrenheit during the day this week, according to MeteoSwiss.

Despite sunny skies and relatively warm temperatures, Dennis Schiergen, the head of racing for the White Turf, expressed optimism that the race would be held. “Now temperatures are quite stable and the lake is recovering,” he said.

On Friday, the first day of the snow polo tournament, Alessandra Fenyves, who was in St. Moritz both as a polo fan and as a freelance magazine journalist from Italy, said the atmosphere was different from previous years. It was her seventh time there.

“It's disappointing,” she said in a telephone interview, adding that she had seen people leaving the stands, which are usually packed. “It's like turning off the music at a party and the waiter comes and takes away the last chips on the table.”