A queen with devil horns, dressed in a rainbow of satin and shimmering gold tulle, sat on a throne along Brooklyn’s Empire Boulevard. Soon, Karen Herbert, 50, would return to being a retired company supervisor.

But on J’ouvert, the daybreak celebration of Caribbean culture traditionally held in Brooklyn before the West Indian American Day Parade, “I am always a queen,” Ms. Herbert declared.

Ms. Herbert, along with other performers, dancers, flag-wavers and musicians, refused to allow the gray weather, or the presence of over 300 light towers and thousands of police officers, to dampen their exuberance.