Illinois Snow Day Calculator: Snow Day Chances Tomorrow by City
Northern Illinois gets far more snow than the south of the state, and the Chicago lakefront can get extra lake-effect snow when winds come off Lake Michigan.
Extreme cold is the other closure trigger here; the January 2019 polar vortex closed schools across the Chicago area.
Forecast data may be out of date. We're working on it; check your local forecast too.
Highest chance in Illinois right now
Lansing, IL
Winter Weather Advisory until Fri 10 AM
Friday
Possible
19%
chance of a snow day
75% chance of a delay
Monday
Unlikely
<1%
chance of a snow day
<1% chance of a delay
Overnight snow 2.5"Usually closes at 4"
- Winter Weather Advisory in effect until Fri 10 AM.
- 2.5" of snow forecast overnight before Friday (8 pm–9 am).
- Lansing usually needs about 4" to close schools (normal snowfall 30" a year).
Estimate, not official. Check your school district for the final decision.
Updated .
Illinois city snow day pages
Snow day chances by city in Illinois
Chance of a snow day:3–9%10–24%25–49%50%+under 3%
Chance of a snow day and of a delay on the next school day for the largest Illinois towns we track, highest chance first. We cover 154 places in Illinois; enter your ZIP code above for any of them.
| Place | Snow day | Delay | Normal snow | Usually closes at |
|---|---|---|---|---|
| Lansing Winter Weather Advisory | 19% | 75% | 30" | 4" |
| Chicago Heights Winter Weather Advisory | 17% | 76% | 28" | 4" |
| Dolton Winter Weather Advisory | 6% | 41% | 32" | 4" |
| Matteson Winter Weather Advisory | 5% | 28% | 28" | 4" |
| Oak Forest Winter Weather Advisory | 2% | 5% | 32" | 4" |
| Blue Island | 2% | 14% | 35" | 5" |
| Orland Park Winter Weather Advisory | 1% | 1% | 32" | 4" |
| Oak Lawn | 1% | 2% | 38" | 5" |
| Kankakee | 1% | 1% | 22" | 3" |
| Lemont Winter Weather Advisory | 1% | <1% | 31" | 4" |
| Bourbonnais | 1% | 2% | 25" | 4" |
| Chicago | <1% | 1% | 37" | 5" |
| Aurora | <1% | <1% | 30" | 4" |
| Naperville | <1% | <1% | 30" | 4" |
| Joliet | <1% | <1% | 21" | 3" |
| Rockford | <1% | <1% | 36" | 5" |
| Elgin | <1% | <1% | 34" | 5" |
| Springfield | <1% | <1% | 21" | 3" |
| Peoria | <1% | <1% | 24" | 4" |
| Champaign | <1% | <1% | 21" | 3" |
| Waukegan | <1% | <1% | 40" | 5" |
| Bloomington | <1% | <1% | 11" | 2" |
| Schaumburg | <1% | <1% | 37" | 5" |
| Evanston | <1% | <1% | 37" | 5" |
| Arlington Heights | <1% | <1% | 37" | 5" |
| Bolingbrook | <1% | <1% | 30" | 4" |
| Decatur | <1% | <1% | 14" | 2.5" |
| Des Plaines | <1% | <1% | 38" | 5" |
| Berwyn | <1% | <1% | 38" | 5" |
| Wheaton | <1% | <1% | 30" | 4" |
| Downers Grove | <1% | <1% | 31" | 4" |
| Plainfield | <1% | <1% | 28" | 4" |
| Glenview | <1% | <1% | 35" | 5" |
| Elmhurst | <1% | <1% | 39" | 5" |
| Buffalo Grove | <1% | <1% | 38" | 5" |
| Moline | <1% | <1% | 35" | 5" |
| Crystal Lake | <1% | <1% | 35" | 5" |
| Bartlett | <1% | <1% | 36" | 5" |
| Belleville | <1% | <1% | 11" | 2" |
| DeKalb | <1% | <1% | 33" | 5" |
Chances are for Friday. Normal snow is the NOAA 1991–2020 annual average near each town.
How much snow closes school in Illinois?
Across Illinois's larger towns, normal snowfall runs from about 11" a year in Bloomington to about 42" in Round Lake Beach, so the amount it takes to close schools varies too: from roughly 2" to 5" of overnight snow in our model.
- Chicago: about 37" of snow a year; usually closes at about 5".
- Aurora: about 30" of snow a year; usually closes at about 4".
- Naperville: about 30" of snow a year; usually closes at about 4".
- Joliet: about 21" of snow a year; usually closes at about 3".
- Rockford: about 36" of snow a year; usually closes at about 5".
- Elgin: about 34" of snow a year; usually closes at about 5".
Compare every state on our how much snow closes school map.
Winter weather alerts and forecaster notes in Illinois
- Winter Weather Advisory Orland Park, Lansing, Oak Forest, Chicago Heights, Dolton, Matteson, Lemont
NWS Chicago/Romeoville, IL · Key Messages
- Prolonged lake effect rain and at times snow showers will continue through at least Saturday morning, especially in northwest IN.
- Rain will transition to snow in the lake effect band tonight and may result in a few inches of wet snow accumulation that will lead to some localized travel impacts late tonight into Friday morning, including the Friday morning commute.
- Cooler temperatures are expected through the weekend before temperatures warm next week.
Excerpt from the National Weather Service Chicago/Romeoville, IL Area Forecast Discussion, issued Nov 12, 2:13 PM CST. Read the full discussion.
NWS Lincoln IL · Key Messages
- The first snow flakes of the season are on tap for locations along and northeast of a Bloomington to Mattoon line late tonight into Friday morning. Accumulations will be minor and confined to grassy, elevated surfaces.
- Below normal temperatures will prevail through the weekend with temperatures gradually warming back above normal by the middle to end of next week.
Excerpt from the National Weather Service Lincoln IL Area Forecast Discussion, issued Nov 12, 1:15 PM CST. Read the full discussion.
Illinois's biggest snow days last winter (2025–26)
Source: NOAA GHCN-Daily, nearest reporting station to each city
Biggest single-day snowfalls in the 2025–26 winter at NOAA stations near Chicago, Rockford, Springfield, Peoria, Champaign:
| Date | Near | Snowfall |
|---|---|---|
| Sat, Nov 29, 2025 | Springfield | 8.9" |
| Sat, Nov 29, 2025 | Chicago | 8.4" |
| Sat, Nov 29, 2025 | Rockford | 8" |
| Sat, Dec 13, 2025 | Peoria | 5.7" |
| Sat, Nov 29, 2025 | Peoria | 5.2" |
| Sun, Dec 7, 2025 | Rockford | 4.9" |
| Sun, Dec 7, 2025 | Chicago | 4.6" |
| Sat, Dec 13, 2025 | Springfield | 4.6" |
Season totals: Chicago 34.1" · Rockford 30.8" · Springfield 26.2" · Peoria 27.7" · Champaign 23.4". Source: NOAA GHCN-Daily.
Largest Illinois school districts
These districts make the official call for schools around Illinois. Their websites post closings and delays first:
Snow days in nearby states
Illinois snow day FAQ
Will there be a snow day in Illinois tomorrow?
The highest chance we see in Illinois for Friday is 19% in Lansing. Enter your ZIP code at the top of this page for your own town; we track 154 places in Illinois.
How much snow does it take to close school in Illinois?
It varies across the state. Based on normal snowfall, our model puts the closing point at about 2" in Bloomington and about 5" in Round Lake Beach. Ice and dangerous cold can close schools with less snow.
What were Illinois's biggest snow days last winter?
Among the NOAA stations we checked, the biggest single-day snowfall in the 2025–26 winter was 8.9 inches near Springfield on Nov 29, 2025.
Where are Illinois school closings announced?
Each district announces its own closings and delays on its website, app and text alerts, and local TV stations publish closing lists. Large districts include Chicago Public Schools, School District U-46 (Elgin), Rockford Public Schools.