MOSCOW – Thousands of Russians celebrating the Orthodox Christian feast day of Epiphany, where worshippers bathe in the icy waters of frozen lakes and rivers, have been forced to cancel their traditional ceremonies amid unusually warm winter temperatures.

Across Russia, the devout and the daring celebrate Epiphany on Jan. 19 by immersing themselves in frigid water through holes cut through the ice of lakes and rivers, imitating the baptism of Jesus Christ in the River Jordan.

Many extol the practice as strengthening both the soul and the body, although rescue workers are on hand in case anyone succumbs to the heart-racing shock of the icy immersion.

But unusually warm temperatures have prompted local emergency services in some regions to cancel events, saying the ice is too thin for worshippers to bathe safely.

Ceremonies have been canceled in areas as distant as the southern Russian region of Saratov and Karelia, almost 1000 miles away on the country’s border with Finland.

Other regions have vowed to carry on with their ceremonies, although melting ice is not the only concern. In the Russian city of Anapa, officials said that the ritual would be held at its traditional place on the Black Sea, despite the thousands of tons of oil that fell into the nearby Kerch Strait on Dec. 15 when two Russian oil tankers sank in bad weather.

Temperatures across Russia have been increasing over the past quarter of a century in line with global warming, says meteorologist Leonid Starkov, who works for Moscow’s Gismeteo.

“A large part of Russia will be warm for these Epiphany celebrations. The average temperature significantly exceeds the norm,” he said. “We are already seeing a thaw in St. Petersburg. In Moscow, we are seeing a thaw. And in southern Russia, the temperature is already reaching 5 degrees or 10 degrees Celsius (50 degrees Fahrenheit).”

Officials have reacted so far by creating alternative sites for bathers, often in smaller rivers and lakes. The water is still cold enough to send some worshippers scurrying to wrap themselves in large towels, while onlookers watch on wrapped in scarves, hats and coats.

But Russians will need to adapt to a future where extreme or unseasonable weather is more common, says Starkov — at both ends of the spectrum.

“Out of the six Epiphany celebrations over the past 25 years where the temperature was colder than usual, five were very cold. Extremes in the weather are increasing,” Starkov said.