Metro had its first cracked rail of 2013 Wednesday morning as a cold snap kept the area shivering.

The crack outside the Green Line’s Naylor Road station happened around 8:30 a.m. and gave riders 10-minute delays as trains single-tracked around the problem, Metro spokesman Dan Stessel said. Crews repaired the rail, which is outdoors, by 10:20 a.m. Metro sensors detected the problem before any trains passed over it, Stessel said.