CHICAGO —City public health officials Tuesday added Kentucky to the list of travel destinations that require Chicagoans to self-quarantine for two weeks after an overnight visit.

California and Puerto Rico were removed from the list that now includes 21 states designated as COVID-19 hotspots for having a weekly average of more than 15 new coronavirus cases per 100,000 residents.

Those states include Alabama, Arkansas, Florida, Georgia, Iowa, Kansas, Kentucky, Louisiana, Mississippi, Missouri, Nebraska, North Dakota, Oklahoma, South Carolina, South Dakota, and Tennessee. Violators could face a fine of $100 to $500 per day, up to $7,000.

Illinois also qualifies as a COVID-19 hotspot with a rolling weekly average of 17 new cases per 100,000 residents. Chicago officials have not required residents to self-quarantine after traveling to other parts of the state.

As of Tuesday, six states —Idaho, Nebraska, Nevada, Texas, North Carolina, and Hawaii — dipped below the coronavirus hot spot level. Some of those states may be dropped from the quarantine list next week, officials said.