Chicago's travel order will be updated once again Tuesday with officials potentially adding or removing states from the order.
Last week, the city added Puerto Rico to the list of places travelers must quarantine from. The week before, four states were added to the order - Wisconsin, Missouri, North Dakota and Nebraska.
The city's travel order is evaluated every Tuesday, with any additions taking effect the following Friday.
States are added to the list if they have "a case rate greater than 15 new COVID-19 cases per 100,000 resident population, per day, over a 7-day rolling average." If they fall below that threshold, they could be removed as well.
Last week, the city's top public health official said three states - Iowa, Kansas and Utah - dropped below the threshold to be on the travel order, and could be removed if those numbers continue to decline.
Chicago's travel order first began on July 6.
The states included are: Alabama, Arkansas, Arizona, California, Florida, Georgia, Idaho, Iowa, Kansas, Louisiana, Mississippi, Missouri, Nebraska, Nevada, North Carolina, North Dakota, Oklahoma, South Carolina, Tennessee, Texas, Utah and Wisconsin. Plus, the most recent addition of Puerto Rico.
Chicago Department of Public Health Commissioner Dr. Allison Arwady said travelers entering or returning to Chicago from "states experiencing a surge in new COVID-19 cases" will need to quarantine "for a 14-day period from the time of last contact within the identified state." Essential workers could be exempt from the quarantine requirement, however, as long as their employer certifies their work in writing.
The order is set to remain in effect until further notice.
New York and New Jersey are also asking visitors from several states, including Illinois, to quarantine themselves for two weeks.
Still, outside of Chicago, Illinois Gov. J.B. Pritzker said the state likely won't require residents who travel to and from neighboring states to quarantine for two weeks solely because of that travel.
"We don't live in a country where you close the borders between states," Pritzker said during the governor's coronavirus briefing. "And we're not going to stop people who live in Illinois and work in Wisconsin from doing so."