"The safety and security of students, faculty and staff is of the utmost importance to schools across the county," SDCOE spokeswoman Music Watson said.
Temperatures were expected to be in the low 40s Thursday in the mountains, with snow falling this morning in some locations at elevations above 3,500 feet. More precipitation was expected later in the day.
A wind advisory was also set to go into effect at 10 a.m. Thursday, with sustained winds of 30 to 40 mph and gusts up to 50 mph possible. The National Weather Service urged drivers to use caution, especially those in high-profile vehicles.