Divvy — which closed during last year’s polar vortex — experienced its coldest day of operation ever Thursday.

“Last year when we closed as a precaution, there were some people who thought it was a great idea and others who said they still wanted to ride,” said Divvy General Manager Elliot Greenberger.

“For us, that was an interesting moment and we realized there were still people who depend on us to get around even in this type of weather.”

As of 3 p.m. Thursday, Divvy had logged 391 bike trips. Thursday’s low temperature was negative eight.

Why ride in extreme cold? For many, it saves time on what would otherwise be long and arduous walks that bookend a commute on a bus or train.

For John Paul Jewell, riding a Divvy bike from his place in Lake View to the Red Line saved him 10 minutes of walking Thursday morning.

“The wind is a little worse when you’re riding, but when it’s this cold out, the difference is marginal because you’re already freezing,” said Jewell, 30, who works in the clean energy finance industry. Your bike seat could be covered in ice, he said.

Divvy riders were not dilly-dallying Thursday, or taking scenic routes. The average bike trip was nine minutes — less than half the 19 minute average from the month of July. The vast majority of riders Thursday were Divvy members.

“It amazes me that people are riding in this weather, and we think it’s great,” said Greenberger, who expected about 800 total bike trips Thursday as riders retraced their routes on the way home.

On Wednesday, riders took 735 Divvy trips. The past seven days there have been an average of 1,000 trips per day. And in December, Divvy experienced an average of 2,800 trips per day.

For warm weather comparison, July was the busiest month for Divvy, with an average of 13,225 trips per day.

The five-busiest Divvy stations Thursday were ones located downtown near Ogilvie Transportation Center and Union Station, which are generally the busiest bike stations in warm weather as well.

The previous low temperature that Divvy operated in occurred Jan. 27 of last year when temps plummeted to negative seven. There were 406 rides that day. Blue Divvy bikes zoomed around on several other subzero days as well.

“It’s not completely virgin territory, but this is definitely the most extreme,” Greenberger said.