The U.S. is in peak flu season, as the CDC releases a map of influenza activity across the country. See which states are at the highest risk of flu activity.

The map of flu activity across the United States continues to darken, both figuratively and literally, as case numbers spike ...

The map of flu activity across the United States continues to darken, both figuratively and literally, as case numbers spike upward in most states, according to the Centers for Disease Control and ...

The map of flu activity across the United States continues to darken, both figuratively and literally, as case numbers spike upward in most states, according to the Centers for Disease Control and … ...

The map of flu activity across the United States continues to darken, both figuratively and literally, as case numbers spike upward in most states, according to the Centers for Disease Control and ...

Flu activity is currently highest in New York City, New Hampshire, Massachusetts, New Jersey, Maryland, Virginia, Ohio, Michigan, and South Carolina, according to the CDC. Jack Forbes / NY Post Design ...

The map of flu activity across the United States continues to darken, both figuratively and literally, as case numbers spike upward in most states, according to the Centers for Disease Control and ...