Illinois Snow Day Calculator

The calculator above is preset for Illinois. Chicago (O’Hare) averages 38.4 inches of snow a year (1991–2020 normals), which puts Illinois in our regular-snow group. For a public school in an average suburban district, the model needs about 6 inches of overnight snow before the chance of a closure reaches 50%. Enter your ZIP code to load the National Weather Service forecast, or change the snow tolerance if your town gets much more or less snow than Chicago (O’Hare).

Illinois snow day facts at a glance

How much snow closes school in Illinois? (model estimate)

Computed with the calculator’s formula for a regular-snow area: public school, average district, no ice, no extreme cold, no timing boost.

Ice changes the picture quickly: in the model, 0.1 inch of freezing rain alone gives about 37% closure odds here, and 0.25 inch about 90%. A morning wind chill of -25°F gives 50% from cold alone. Heavy snow between midnight and 6 a.m. counts 25% more, because it is still falling when districts decide around 4–6 a.m.

Reported thresholds and cold-day policies in Illinois

These come from our snow day thresholds dataset. Most are news reports, so they describe policy as reported at the time, not necessarily today.

• Chicago Public Schools — Snow: Closed for snow only 4 times 1999-2014, each with 20+ inches on the ground. Cold: Closed four times in Jan 2014 for extreme cold (not snow). (news; source↗; CBS Chicago 2014-01-30)
• Chicago suburbs outside Cook County — Snow: Roughly 12 inches. (news; source↗; CBS Chicago 2014 (summarizing crowdsourced map))
• Central Illinois and Indiana — Snow: About 3 inches. (news; source↗; CBS Chicago 2014 (summarizing crowdsourced map))

Remote learning days in Illinois

Allowed. 105 ILCS 5/10-20.56: board-adopted e-learning program (public hearing, ROE verification, 3-year approval); e-learning days may replace emergency days but may not exceed the number of emergency days in the approved calendar; at least 5 clock hours of instruction or school work per day. The statute as we read it sets no fixed number of days. (statute↗) Because individual districts decide whether to use remote days, the calculator asks whether yours usually goes remote and splits the closure chance into a day off and a remote day.

Minimum school year in Illinois

The Education Commission of the States’ 2023 comparison lists these minimums for Illinois (they may not reflect later legislation):

• Days: 185
• Instructional hours: Not specified

Days lost to closures count against that minimum, which is why districts that use up their snow days typically add make-up days at the end of the year — and why remote-day rules matter.

Where to check official closures

Only your district can close school. Check its website, app or text and email alerts first. We don’t list district links for Illinois because we haven’t verified them; this page and its calculator are an estimate, not an announcement.