If you’ve ever planned a road trip vacation, you may have felt that you needed to pack for every season. But Brian Brettschneider, an Alaska-based climatologist and prolific mapmaker, has found a way around that.
While Brettschneider says no one has navigated the full expedition, which would involve a journey through 26 states and five provinces and two territories in Canada, several people have tried portions of it.
“It’s a year long, so you need to be basically retired or otherwise have a free year to do it,” Brettschneider said in an interview Wednesday. “I have heard from people who have done segments, like the Appalachian chunk.”
Brettschneider says he came up with the idea for this sort of project in 2015 when thinking about how, thanks to shifting seasons, a belt of relatively temperate weather would oscillate north and south over the course of a year.
“I kind of noticed that you could kind of trace a path around the country where there was a constant temperature,” he said. “Seventy seemed like a nice number where you can trace that throughout the year.”
So he did. He calculated historical averages for the period 1991 to 2020, and then used those to chart a course — or rather several courses. In addition to the U.S.-Canada route (shown above), which covers more ground and also includes a visit to Alaska, Brettschneider offered a few options for those hoping to remain within the Lower 48.
One of them, the coastal route, begins in Tampa, features a drive up Interstate 95 to Boston into the late spring, a hop toward the Great Lakes, passage through the Upper Midwest and Columbia River Basin during the summer and then meandering through the Four Corners and Desert Southwest into December. That one is 7,468 miles.
A slightly shorter (7,064 miles) interior route would begin in Texas, include a slow northward progression toward the Canadian border and then require spending some time in the Rockies and High Plains.
But the ultimate journey — that includes Canada and Alaska — would begin in San Diego. January would be spent taking Interstate 8 east toward Phoenix. Then comes a trip to El Paso in February. March, April and May include a slow east-northeast journey through the heartland, Midwest and Appalachians, visiting the Virginia Blue Ridge, Canton, Ohio, and Chicago.
In June, the intrepid adventurer would pass through International Falls, Minn., before crossing the border and swinging through Winnipeg and Edmonton in Canada. Since summer temperatures rise most quickly in June, travelers would have to move more than 100 miles per day on average to “outrun” highs above 70 degrees — covering 3,424 miles during the month. By the end of June, travelers would have to be in Fairbanks, Alaska, which also would have meant a trip through the Northwest Territories, British Columbia, Alberta, Saskatchewan, Manitoba and Ontario.
The remaining six months are spent on a return journey to Florida, with jaunts through Idaho, the Rockies, the Great Plains and the Southeast.
The maps displaying these routes were published on Brettschneider’s website Tuesday. They represent an update from maps he published in 2015 incorporating the latest available 10 years of climate data; his 2015 maps were based on 1981-2010 climate averages, while his 2023 maps use data from 1991-2020.
In 2015, Brettschneider also created a 10,000-mile road trip following 80-degree temperatures for the Capital Weather Gang.
Brettschneider has been shocked about how popular his maps have been.
“I never expected it to take off,” he said. “But there are lots of intersections with [people’s] interest. There’s been kind of a road tripping hallmark of American culture since the 1950s. Everyone’s done a road trip.”
Since he initially published the first renditions of his maps in 2015, Brettschneider estimates some 20 million people have seen them in some capacity.
“Quite a number of people asked ‘are you going to update this?’ so I figured I had a little time last week, and I decided to update it,” he said. “It’s really been interesting that, over the years, it’s taken on a life of its own.”
On his website, Brettschneider wrote that even though his new maps take into account another decade of climate warming, the routes haven’t shown much change. “[T]he shift in 70°F temperatures between 1981-2010 and 1991-2020 is very slight,” he wrote. “It’s just too short of a time period to capture the distance change.”
Jason Samenow contributed to this report.
