During one of Carter's first visits, the locals told him: Don't sweat the cold. It's not considered harsh until the temperature hits 40 below.
"The good news is, I now know where Fahrenheit and Celsius converge," Carter said of the reading, which is the same in both systems. "The bad news is, I now know what that feels like."
On Wednesday, Carter was at home in Ewing, N.J., chopping vegetables to cook a warm pot of chili, and pondering a cool spot on the other side of the world. He's on sabbatical this semester, working on a book about horse-racing in more temperate Shanghai.
What's fascinating about Harbin winters is not the crazy numbers, Carter said. It's that people there treat the cold like a natural part of the landscape.
It's not like St. Paul or Chicago or Albany, where systems of underground tunnels and skyways shelter people as they move from building to building. Or even like Philadelphia, where snow and cold close governments, roads, and businesses.
In Harbin, the schools don't close in brutal cold because otherwise, schools would never open. People bundle up and get on with their day.
The high in Harbin on Wednesday was 5, the low 4 below zero. By Monday, the low is expected to be about 20 below.
"You do get used to it," Carter said. "I brought thick winter boots. Everyone thought that was hilarious. They just wore regular shoes."
Harbin is huge, home to nearly six million people with five million more in the near suburbs. It's the capital of Heilongjiang province, which sits as far north as one can go in China before crossing the Russian border into Siberia.
Harbin's American sister cities include - to no surprise - Anchorage and Minneapolis.
But it's the city's lesser-known Russian origins that drew Carter there in the 1990s, where he practiced skating on a frozen soccer field and watched people skim the ice from their teacups in the chilly local library.
Since spending that first long, brutal winter, he scheduled his more recent trips for spring and summer. In March, for instance, the average daily temperature soars to 23, which he said actually seemed mild.
Harbin is a Manchu word that means "place for drying fishing nets," and for much of its history it was good for little else. The city was established in 1898 as an extension of the Trans-Siberian Railway. By the 1900s it was essentially a Russian city on Chinese land, leading local Chinese to stage violent protests, explored in Carter's book, Creating a Chinese Harbin.
He's written books, essays, and articles on China, and in 2011 was one of 20 scholars chosen for the public-intellectuals program run by the National Committee on United States-China Relations in New York.
But Harbin calls, and Carter continues to study the smoldering, nationalist resentments in what's now a rust-belt city. Harbin gets by on steel and machine-part production, while at the same time pushing its Russian past, trying to lure tourists to see onion-dome churches and cobblestone streets.
He's seen the city become more violent, and more drunk, probably because the cold does nothing to warm the hearts of Chinese, Russians, and Koreans pressed into close quarters.
"As an armchair sociologist, I'd say people are inside a lot, so they end up drinking a lot."
A nice place?
"Not really," Carter said. "It's an interesting place. . . . It's really cold, and you prepare yourself for it."