The 300,000 extra travelers since last year alone could result in delays and traffic — as could heightened security in the wake of recent international terror attacks. And meteorologists say Mother Nature isn't expected to show any mercy on some parts of the country.
Winter storm warnings were already in place on Monday in Montana, northern Idaho and eastern Washington, which could get smacked with snow in high elevations, according to the National Weather Service.
But when the weather really gets rough is in the middle of the week, right in time for Wednesday — the biggest travel day of the year, according to AAA.
"We could have freezing rain and ice through the Plain states into Friday," said Brian Fortier, a senior meteorologist at the Weather Channel.
"Near-blizzard conditions" will likely cause delays on Interstate 15 in Utah, Idaho, and Montana; Interstate 80 in parts of California, Nevada, Utah and Wyoming; Interstate 90 in Montana; and possibly sections of Interstate 70 in Colorado, according to Weather.com.
On the bright side, Fortier said, the bigger cities and busier airports in the East —including Atlanta, Washington D.C., Philadelphia and New York — "all look good for Wednesday travel." He added that the overall holiday forecast "could be worse, but it could be better."
Later in the week, a cold front will be followed Friday by snow and ice in western Kansas, western Oklahoma, and the Texas Panhandle, Weather.com reported.
Some traveling Saturday won't be out of the woods — or the tundra — either. Freezing rain and snow are expected to create dangerous driving conditions in western Texas.
"It'll be a nightmare for people who have to go through the ice," Fortier said. Still, he said it's early yet to scrap travel plans or expect the worst since the forecast could change. "There are a lot of ingredients and a lot of details that have yet to be determined for later in the week," he said.