Some Chicago-area schools have already announced closures or shifts to e-learning for this week in advance of dangerously cold temperatures and wind chills as low as -40.

The announcements come as the National Weather Service issued an extreme cold warning for all of northeastern Illinois and southeastern Wisconsin, with expected wind chills as low as -30 to -40 degrees. According to the NWS, the warning will go into effect at 3 a.m. Friday.

Ahead of the temperature plummet, here’s which schools have announced closures so far, how to check the status of your school and more.

Are Illinois schools closed tomorrow?

No closures or e-learning plans were in effect for Thursday, but some schools have already announced closures or possible closings for Friday, according to the Emergency Closing Center.

Bridgeport Catholic Academy in Chicago said “due to the extreme cold” it will be switching to eLearning for Friday.

“Students will be reminded to take home any necessary materials tomorrow,” the school said in an alert to parents.

River Trails School District 26 in Mount Prospect issued a note to families saying they are “closely monitoring the predicted extreme cold temperatures.” A final decision was expected by noon Thursday.

In the northern suburbs, Lake Forest Community High School issued a similar message, saying a decision about Friday classes would be made at 12 p.m. Thursday.

“Updates on Sat., Jan. 24 activities, including the LFHS Winter Formal, will also be communicated by noon on Thursday, Jan. 22,” the school said.

Grace Lutheran School in River Forest, Ashburn Christian Academy in Orland Park and St. John The Baptist Catholic School in Winfield will all be closed Friday, per the Emergency Closing Center.

Will Chicago Public Schools close?

The threshold for when weather is wintry enough to close schools isn’t decided by a particular degree of temperatures or amount of snowfall, instead, several factors typically go into the decision making process on if a school will close.

For Chicago Public Schools, the district said it “works closely with the experts at the City’s Office of Emergency Management and Communication (OEMC) to help guide decision-making when it comes to school closures.”

The following criteria is evaluated before a decision is made:

• Air temperature and wind chill
• The amount of snow and ice on the ground
• The accessibility of buildings and roads
• Potential issues with heating/cooling systems or power outages
• The ability to transport students safely on buses

CPS noted that its maintenance crews regularly test equipment and heating systems to ensure they’re working properly, the district said, and every school has a snow removal plan to keep sidewalks, walkways and parking lots clear for students and staff.

“CPS also closely monitors weather forecasts and makes all decisions related to school closings based on the health and safety of our students,” their website states.

How to check Illinois school closings

Families can check for the latest on their school using the link below:

CHECK SCHOOL CLOSINGS HERE (NOTE: If you are accessing this link from our app, please go to your mobile browser).

Many school districts also post about closings on social media and on their website homepage, and communicate with their school community via phone, email and text message notifications.