The number of passengers stepping onto planes at Jackson Hole Airport increased 17 percent in January — a record increase over last year.

Airport officials said the year-over-year uptick was unprecedented.

“I don’t think I’ve ever seen that big of a jump,” said airport director Ray Bishop, who’s been on the job more than six years. “It’s usually 2, 3, 4 percent, and maybe sometimes 7, 8, 9 percent. But I don’t think I’ve ever seen 17 percent.”

Reduced air traffic in 2012 suppressed Jackson Hole Airport’s passenger numbers, leading to a bigger jump this year.

More than 24,290 passengers took off from Jackson’s airport last month. Last year, just under 20,690 passengers were enplaned in January, down from nearly 24,200 passengers the same month in 2011.

Bishop didn’t pin the increase on any single factor.

“It was absolutely unexpected,” he said. “We started the Newark [New Jersey] service and we thought that would give us a boost.”

The weather — and favorable conditions for skiing late in December — could also have played a role, he said.

“My personal feeling is we’ve had some pretty good snow and good skiing and I do think there’s a connection.”

Jerry Blann, Jackson Hole Mountain Resort’s president, confirmed Bishop’s hunch.

“We had a real strong finish to the holiday season into the second week,” Blann said. “Ever since then, it’s been about average.”

There were a record-high number of skiers in December, Blann said. January ended with the sixth-most skiers in the resort’s history, he said.

While the number of flights landing in Jackson Hole also rose last month, it was a more modest increase. Some 299 commercial airliners touched down in January, equal to 6 percent more than the January 2012 total of 281.

About 78 percent of seats were filled on planes flying into the valley last month.