A shopper wearing a protective mask as a precaution against the spread of the coronavirus selects fruit at the Reading Terminal Market in Philadelphia.Matt Rourke | APPhiladelphia health officials are keeping the city’s newly reinstated indoor mask mandate in place despite a federal judge’s ruling in Florida that struck down a federal requirement to wear face coverings on public transportation.The city of brotherly love became the first major city in the U.S. on Monday to reinstate its Covid-19 mask mandate for indoor activities as the highly contagious omicron BA.2 subvariant drives new Covid cases higher across the U.S.Many cities and states lifted mask mandates in February and March as cases plummeted from a pandemic peak of about 808,000 average new cases a day in mid-January to about 35,000 new cases a day this week. But infections across the U.S. have started to edge up in recent weeks, and cities like Philadelphia are experiencing a new surge in cases.The Transportation Security Administration on Monday said it would stop enforcing mask rules hours after U.S. Judge Kathryn Kimball Mizelle in Tampa, Fla., ruled that the Centers for Disease Control and Prevention overstepped its bounds when it mandated face coverings on planes, trains, buses and other forms of public transportation.Masked and unmasked travelers line up at a security checkpoint after the Biden administration announced it would no longer enforce a U.S. coronavirus disease (COVID-19) mask mandate on public transportation, following a federal judge’s ruling that the 14-month-old directive was unlawful, at Ronald Reagan Washington National Airport in Arlington, Virginia, U.S., April 19, 2022.Kevin Lamarque | ReutersWhile the ruling may lift Philadelphia’s mask rules on public transportation, the mandate still remains in place for other indoor venues, including restaurants, gyms and businesses.”We are evaluating the implications of this latest ruling and will provide further clarity around masking on transit in Philadelphia when available. This ruling does not impact the city’s mask mandate for certain indoor places.” James Garrow, director of communications at the Philadelphia Department of Public Health, said in an email to CNBC. Philadelphia reinstated its mask mandate after cases there jumped 50% from April 1 through April 11, health officials said. Hospitalizations were steady as of April 11, but have since rapidly risen. The number of people hospitalized with Covid there almost doubled last week, from 46 people on April 11 to 82 people on Monday — what health officials called a “worrisome sign that this wave could be more dangerous than we had hoped.””We have been watching this wave of the pandemic sweep over Europe and it looks like it’s coming to Philadelphia now,” Health Commissioner Dr. Cheryl Bettigole said in a statement Monday. “We need to do whatever we can to make sure that our most vulnerable neighbors and loved ones stay safe. Each and every one of us has the ability to save lives today by putting our masks on and helping to stop the increase in cases.”The city had been at Level 1, or “all clear,” after the initial omicron surge receded, meaning that mandatory measures such as indoor mask mandates had been lifted, according to Philadelphia’s public radio station. But the recent uptick in cases driven by BA.2 moved the city to level two, or “caution,” which requires masks. The mask mandate will be lifted once Philadelphia meets the thresholds of the “all clear” level again, according to the city. Other major city leaders have been hesitant to reintroduce the politically unpopular requirements.In Chicago, the Department of Public Health said the return of a mask mandate is not expected in the near future, even as the city sees an uptick in cases.”That is not something that we’re talking about at this time,” said Dr. Amaal Tokars, acting director of the department, according to NBC Chicago. “However, I would never say that nothing has passed, but we are going to do what we think is wisest and best based on the current circumstances that we see.”In Massachusetts, the public health commissioner said there are no plans at this time to reinstate a statewide mask mandate. Hawaii’s governor also said last week he is not considering reimposing a mask requirement for indoor public spaces. The state was the last to lift its mask mandate at the end of March. Similarly, public health officials from the state of Washington said the return of the mask mandate is not “in our best interest.” “I think what’s pretty clear is the public is pretty tired of mandates, and so I think (we) really need to use that power judiciously,” said state epidemiologist Dr. Mike Lindquist in an interview on TVW, Washington’s public affairs network. CNBC’s Spencer Kimball contributed to this report.