![A Denton diner that made headlines for its strict and humorous mask mandate will soon close its doors for good.](https://media.nbcchicago.com/2021/08/Diner-Closes-2.jpg?quality=85&strip=all&resize=320%2C180)
Chicago's new mask mandate is set to begin Friday, but how long will it last?
Chicago Department of Public Health Commissioner Dr. Allison Arwady said the city would have to see less than 400 COVID-19 cases per day "consistently" and be below the federal "high transmission" tier for officials to remove the mask requirement.
"When we drop back to 'substantial risk,' we would expect the mask (mandate) would drop back to a recommendation," Arwady said.
The U.S. Centers for Disease Control and Prevention uses two measures to group counties into the four levels of community transmission: the number of new cases per 100,000 residents and the percent of COVID-19 tests that are positive over the past week.
If a county has reported 50 to 100 cases per 100,000 residents over a seven-day period or has a positivity rate of 8% to 10%, it falls into the "substantial transmission" tier, while those reporting 100 cases or more per 100,000 or have a positivity rate of at least 10% are labeled as "high transmission." Those are the two groups for which the CDC recommends mask-wearing.
As of Thursday, Chicago was averaging 462 COVID cases per day, which is a 25% increase from last week. The city was also seeing a 4.7% positivity rate, which has risen nearly a full percentage from the prior week.
According to data from the CDC, Cook County was averaging about 120 COVID cases per 100,000 residents as of this week, with a 4.49% positivity rate. Both metrics have increased over the past seven days.
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All residents age 2 and older, regardless of a person’s COVID vaccination status, will be required to wear a face covering while indoors in Chicago starting Friday.
For where you have to wear a mask and what you need to know about rules on face coverings in Chicago, click here.
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