By KIRK JOHNSON

New York Times

ANCHORAGE, Alaska >> The Iditarod dog-sled race has gripped the imagination here for a long time, partly because it captures the idea, cherished by Alaskans, that a true-north wildness lies just over the horizon, and anyone getting there must first face a harsh gantlet of ice and cold.

Snow delivered by train never figured into that image.

But there it was, four or so inches of dirty snow with the consistency of sand, dumped overnight by trucks onto a downtown street for the 85 teams of sled dogs and drivers, called mushers, to parade through for the race’s ceremonial start Saturday morning. The parade was only 3 miles long instead of the usual 11 because, despite the train delivery of tons of snow from Fairbanks, there still was not enough to go around.

Winter here is changing rapidly. Of the six warmest November-to-January seasons in Alaska since 1925, three have been in a row, including this one. Anchorage this year had its fourth-warmest February on record — at 29.9 degrees, almost 10 degrees above average — with little snow for weeks.

The race, formally known as the Iditarod Trail Sled Dog Race, began Sunday from the town of Willow, about 50 miles north of Anchorage.

In trekking nearly 1,000 miles to the finish line in the old gold-rush town of Nome, mushers and their teams commemorate an event that captivated the world in 1925, when a sled team, led by a dog named Balto, raced through blizzards to deliver lifesaving serum to Nome during a diphtheria outbreak. The rescue made headlines around the world, and earned Balto a statue in Central Park in New York. And since 1973, the competitive race has been run to celebrate that trek.

Local historians say the race takes its name from the Iditarod River, which, in turn, means distant or distant place in the language of the indigenous people.

There is $70,000 in prize money for this year’s winner, according to the race organizers.

Scott Janssen, who owns funeral homes in the Anchorage area, said there was little doubt in his mind that northern weather is rapidly and fundamentally changing, especially here.

“We’ve become Seattle,” said Janssen, 54, who calls himself the Mushin’ Mortician. He has finished the Iditarod twice in five attempts. “We get snow and then, in the afternoon, it melts,” he said.

While it might sound paradoxical, milder weather does not make the Iditarod safer, easier or more predictable.

For the 1,000 or so sled dogs, for example, heat is a much bigger concern than cold or even lack of snow, veterinarians and mushers said. The animals are bred and trained to run in harsh conditions and are happiest at temperatures of zero to minus 10. Even their diet during the nine days or so that it normally takes to complete the race is formulated to mimic the meaty diet that Balto knew.

Just one sunny day in the 30s or 40s can raise concerns about overheating and dehydration for the dogs, said Stuart Nelson Jr., the chief veterinarian for the race.

“The biggest concern is overheating,” said Nelson, who said that veterinarians examine the dogs at each checkpoint, and even conduct random urine tests to check for drugs such as painkillers or stimulants. To test for dehydration, doctors pinch a dog’s shoulder skin: If it pops back into place quickly, all is well; if the skin returns more slowly, the dog is stressed. The doctors can pull from the race any dog they feel is not well.

This winter has also lacked what Alaskans call “deep cold,” in the range of minus 50 or lower, which may have implications for the trail. No weather station anywhere in the state, even in traditionally frigid spots of the interior, like Fairbanks, has recorded anything colder than minus 30 this year. Spring arrives in two weeks, and if that mark stands, it will be the first time in at least 100 years that no place in Alaska saw winter temperatures fall to minus 50, according to National Weather Service records.

Fewer days of such deep-freeze conditions creates the possibility of open water on the Iditarod course, which runs through the typical Alaskan bush mixture of rivers, bogs, lakes and swamps.

In any event, the sharp variability of the course’s terrain — and thus the need to expect the unexpected — is probably going to be as ferocious as ever, said Stan Hooley, the chief executive of the Iditarod Trail Committee.

Last year, for example, was so snowless in a crucial area of the Alaska Range mountains that the start of the race was moved to Fairbanks, 225 miles from its traditional beginning north of Anchorage. But warmer temperatures at the start quickly turned extreme when teams were caught in temperatures of minus 50, Hooley said.

The racers are also adapting their strategies, he said, to a hotter, more variable Iditarod.

“What you’ll see from a strategy standpoint is that many of the teams will rest much more significant amounts during the daylight hours, and do most of their traveling at night when temperatures are colder,” Hooley said.

He said dog health and safety drive those sorts of decisions, just as it did in the old days when survival — not winning a race — was the main consideration.

“The fact that we’ve got warmer temperatures means there’s much greater emphasis by the individual competitors to make sure that the dogs are adequately hydrated, to deal with the stress,” he said.

Janssen, the funeral director, said he was prepared for any kind of race that might unfold, but that for now he was happy. Last year’s race, starting in Fairbanks, went well.

“I love running on Fairbanks snow,” he said.

© 2016 The New York Times Company