A series of live maps from Windy.com highlighted which parts of the U.S. were experiencing elevated levels of air pollution on Friday. The maps showed data for multiple types of pollutant, including ...

A contagious new COVID-19 variant called NB.1.8.1, aka "Nimbus," is now dominant in the United States, CDC data show. What to ...

An interactive tool from Johns Hopkins University lets you track the disease as the U.S. suffers its worst year in decades. The United States is experiencing its worst measles outbreak in three ...