COVID by the Numbers: What Happened Last Time Illinois Removed Its Mask Mandate?

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On Monday, the state of Illinois will move forward with a plan to remove its indoor mask mandate, meaning that businesses will be able to decide whether or not to require customers to wear facial coverings.

The decision is a significant one, as it’s been nearly six months to the day since Illinois brought back its mask mandate in Aug. 2021 in response to the delta variant surge.

Previously, the state had lasted just over three months with a modified or eliminated mask mandate, having removed the requirement for facial coverings for vaccinated individuals in May 2021 and fully repealing all COVID mitigations in June 2021.

The question now on the minds of many Illinoisans is a simple one: what comes next? What can we expect from COVID metrics with facial coverings no longer required in indoor spaces?

To help shed some light on that question, here are some figures from the summer of 2021, when facial coverings were no longer required in Illinois.

Key Dates:

May 18, 2021 – Illinois changes rules, removing fully-vaccinated individuals from mask mandates

June 11, 2021 – Illinois moves to Phase 5, removing all COVID mitigations

Aug. 30, 2021 – Illinois brings back mask mandate as delta surge rages

Illinois is expected to end its indoor mask mandate early next week, should COVID-19 metrics continue to decline statewide. When will the mandate be lifted, where will you still need a mask and is the same timeline expected in Chicago?

COVID Case Trends:

When the state first tweaked its mask mandate to remove fully-vaccinated individuals, Illinois was averaging 1,537 new COVID cases per day. On June 11, when the state moved to Phase Five, Illinois was down to just 381 cases per day, representing a decrease of 75.2% in less than a month.

On June 23, the state hit its lowest-ever COVID case rate, with 222 Illinois residents a day testing positive for the virus.

From that day forward, increases began to slowly occur. On July 4, the state had seen its case numbers creep upward to 307, but then the pace of increase began to accelerate.

On July 11, the state saw its average rise to 511, representing an increase of 66% within one week. The next week, cases rose by 52.8% to 781. Cases then rose by 58% the next week to 1,234 per day.

By the time the mask mandate had returned, the state was at 3,871 COVID cases per day.

After falling through September and into October, cases began to surge again, with the omicron variant helping to push the average number of daily cases to a staggering 32,501 on Jan. 12.

Then, even more quickly than they had risen, cases began to fall, and on Friday the state reported that it is averaging 1,861 new cases per day, the first time the daily average has fallen below 2,000 since Aug. 2, 2021.

The city of Chicago has announced that it will end its requirements for masks and proof-of-COVID-vaccination in many indoor settings, but there will still be places where facial coverings will be required.


On May 18, 2021, the state of Illinois had 1,518 patients in hospitals that had tested positive for COVID. That number had dropped to 684 on June 11, a decrease of nearly 55% within a month’s time.

Illinois saw its hospitalization numbers hit their lowest level on July 4, when 380 individuals were hospitalized.

That number began to slowly rise in July, increasing by nearly 90% to 721 by July 25, but then the pace began to quicken in August, and by the time the state reinstituted its mask mandate, there were 2,203 patients hospitalized.

Following a similar pattern to that of cases, hospitalizations began to decrease in September as the delta variant slowed, but more patients began seeking care in October and hospitalizations began to skyrocket, topping out at 7,380 on Jan. 12.

Six weeks later, the state is now at 1,143 patients hospitalized, a decrease of nearly 85% during that time. That hospitalization rate is the lowest the state has seen since Aug. 2, 2021, and is 25% lower than the hospital census when fully-vaccinated Illinoisans were removed from the mask mandate last May.

ICU Usage

On May 18, 2021, the state had 405 ICU patients that were COVID-positive. By the time Phase Five began on June 11, that number had fallen to 186.

The number continued to drop through the rest of June and into early July, and by July 7, just 76 ICU patients in the entire state were COVID-positive.

Like hospitalizations, ICU admissions began to slowly climb in mid-July, and by July 28, there were 179 patients in intensive care units.

Admissions began to increase more quickly after that, and by the time the mask mandate returned, there were 527 patients in ICU’s with COVID, representing an increase of 194% in just over a month’s time.

During the omicron surge, Illinois topped out at 1,177 patients in ICU beds due to COVID. Now, the state has seen an 82% decrease in ICU patient counts, with 211 such hospitalizations currently reported.

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