More than 2.1 million affairs occurred in the US last winter. Here are the cities where cold-weather cheating is most likely to happen.

• During the winter of 2017, there were 2.1 million new affairs in the United States, according to data from married dating website Ashley Madison.
• Ashley Madison polled its users to determine the US cities where cheating most often occurred at this time, and places like Pittsburgh, Pennsylvania and Bloomington, Indiana made the list.
• "A lot of times people living in smaller hubs spend a great deal of time traveling for work and use that time to connect with people who are not their spouse," Isabella Mise, director of communications for Ashley Madison, said in a release.

With cold and dark winter months comes a tendency for couples to stay inside and get close in bed. And sometimes with someone other than your partner. Last winter, there were 2.1 million new affairs in the United States, according to data from married dating website Ashley Madison.

To determine the top places where people cheat in the winter, Ashley Madison analyzed sign-up data between December 21, 2017 and March 20, 2018 to find the most popular places for wintertime extramarital affairs.

Many of the places that made the list were smaller towns and cities like Pittsburgh, Pennsylvania and Bloomington, Indiana.

"A lot of times people living in smaller hubs spend a great deal of time traveling for work and use that time to connect with people who are not their spouse," Isabella Mise, director of communications for Ashley Madison, explained in a release.

Here are the top 10 cities for cheating during the winter.

Alexandria, Virginia

The 10th most popular city for cheating in the winter months is Alexandria, Virginia. According to Paul Keable, Ashley Madison's vice president of communications, East Coast destinations like Alexandria were the most popular for wintertime affairs.

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Pittsburgh, Pennsylvania

Pittsburgh, Pennsylvania was the ninth most popular winter cheating location and with the city's cold temperatures during the winter months, it makes sense.

"Having a warm body to snuggle up with in the winter allows people to avoid feeling devoid of the human and social interactions they mentally and physiologically crave," Caitlin Bergstein, a matchmaker for Three Day Rule, told Brit+Co when explaining why people tend to pair up more in the winter.

Bloomington, Indiana

Bloomington, Indiana ranked eighth on Ashley Madison's list. The city has a population of 85,000 and many live there while they attend Indiana University.