St. Elizabeth Catholic High School in Thornhill will not be open for the first day back to school.
The York Catholic District School Board says there will be no access to the school all week because of repairs caused by a fire on December 29.
There was no one at the school, located at 525 New Westminster Dr., at the time of the fire.
The school's website says the cause appears to be electrical, and may be linked to a power outage caused by the ice storm.
Students and staff will not be relocated during the closure.
The school is set to reopen Jan. 13.