CHICAGO (CBS) — A north suburban school superintendent apologized to parents Thursday, after cancelling classes due to the cold weather, after he had second thoughts about his decision.

Students returned to class Thursday at Wilmette Public Schools District 39, a day after the schools were closed because of near-zero temperatures outside.

Wednesday night, Supt. Ray Lechner sent a letter to parents, admitting he caved in to peer pressure to close schools.

“I wasn’t in favor of closing school yesterday, but when I saw a domino effect of school after school after district closing, I kind of fell to the pressure,” he told WBBM Newsradio’s Bernie Tafoya. “We had one school closing, and then another school, and then another, and then [Chicago Public Schools] closed, and that really gives us pause, and then Evanston’s schools closed, and suddenly we were the only ones that would possibly be open, so we thought we should follow suit.”

Lechner said, after he went to work Wednesday, and felt the weather wasn’t as bad as predicted, he felt classes could and should have been held, so he decided to reopen schools on Thursday.

RELATED: Lechner’s Letter To Parents

He said snow, and its impact on safe roads, typically is the biggest factor in deciding whether to close schools in winter.

“Really the biggest factor is snow, and travel, and that type of an issue; because our schools are warm, our homes are warm, we have warm clothing, we have ability to get kids to and from school,” he said.

Lechner said his district is smaller geographically, and doesn’t rely as much on busing students as other districts, as many parents drive their children to school.

He said a decision on whether to close school Friday, when the afternoon temperatures are expected to be colder than Thursday afternoon, will be made sometime Thursday evening.