All classes were canceled Tuesday and Wednesday for the first time since 2014 after the university met the weather criteria to do so, but many students don’t know, or understand, what those criteria are.

Class cancellations were originally implemented from 5 p.m. Tuesday to noon Thursday due to a wind chill advisory in effect during those times. When the wind chill advisory was extended through 6 a.m. Tuesday, the University made the decision to cancel classes for all of Tuesday.

“We based our decision on when to close campus on the National Weather Service notice that a wind chill warning would begin at 6 p.m. Tuesday,” according to an email to students from Pam Cain, interim senior vice president for Finance and University Services.  “This morning the National Weather Service announced that a wind chill warning for central Iowa would begin at 6 a.m. today instead of 6 p.m.”

National Weather Service forecasts did not change between the time of their first and second cancellation decisions, National Weather Service meteorologist Andrew Ansorge said.

“Our forecasts have stayed the same since Sunday,” Ansorge said. “They have been accurate and on track as of now.”

While there were no changes in temperature forecasts, National Weather Service meteorologist Allan Curtis said the wind chill advisory might have been extended to reflect temperatures falling slightly faster than expected to later forecasts showing potential wind chills surpassing -50 degrees.

“You hear people say you can get frostbite in 10 or 15 minutes, but in those temperatures it could take just minutes for frostbite to set in,” Ansorge said.

The decision to close goes through the university’s senior vice president for University Services, with consultation from the president, provost, public safety officials, the Iowa Department of Transportation, city of Ames, CyRide and maintenance staff.

What makes this cancellation different from other cancellations is that the decision was made based on the dangerously cold weather, not their usual criteria. The Closing and Cancellations policy states that “generally, when CyRide is operating and streets and sidewalks are passable, the university remains open.”

Closing classes for two full days also affected more than just people walking to class; the city of Ames reduced the circulation of CyRide and canceled other city activities. All city programs and activities were canceled Tuesday and Wednesday along with closings of the municipal pool and the Ames/ISU Ice Arena, according to a press release from the city of Ames.