This comes as President Joe Biden is dealing with his recent diagnosis.
Health experts are urging people to stay up-to-date on COVID vaccinations.
It's a trend that's happened since 2020: When temperatures rise, so does the number of COVID cases.
And local doctors report seeing a summer surge.
Dr. Sharon Welbel is an infectious disease specialist at Cook County Health.
"We are seeing increased rates of test positivity, which means we're seeing more people with COVID than we have in the previous few months," Welbel said.
According to data from the Centers for Disease Control and Prevention that was analyzed by the ABC7 Chicago data team, test positivity across the country has been on an uptick since mid-May, when it was 3.5%.
The latest data show that it's more than tripled to 12.6%.
A group of variants, collectively knowns as FLiRT, makes up a majority of COVID infections, and doctors say, at this point, severity is low. They say most of the cases they're seeing are outpatient.
"That said, emergency department visits and hospitalizations have also gone up slightly," Welbel said.
Dr. Marc Sala, with the Comprehensive COVID Center at Northwestern Medicine, says that while COVID has been grouped with other respiratory viral illnesses like the flu and RSV, it's still important to know what you have, and either test with an at-home kit, or go to the doctor's office.
"There's going to be a certain proportion of people, 5% at any given time, according to the CDC, who develop long-COVID. That is not the case of influenza or other viruses," Sala said.
If you do test positive, protocol depends on your place of work, but general guidance is returning to the job after going 24 hours without a fever, and masking for at least five days.
The COVID vaccine will be updated this fall to address the new variants.
Doctors say it's possible that, like the flu vaccine, it will be recommended to get a COVID vaccine every year.