Gregory Stanley Forbes was born on August 22, 1950, in Latrobe, Pennsylvania, United States. He is an American citizen. Raised in Latrobe, he grew up in a Roman Catholic household, although he did not personally identify strongly with religious practices. His mother was a homemaker, and his father worked as a social worker in their hometown.
As a child, Forbes had a wide range of interests. He played Little League baseball, learned to play the clarinet, and developed a deep passion for reading—particularly books about the weather. This early interest would later shape his career path. His fascination with meteorology began in the seventh grade when a classroom discussion on weather sparked his ambition to become a meteorologist.
Greg Forbes is approximately 1.81 meters tall and weighs around 75 kilograms, which is considered a healthy weight for his height. Born under the astrological sign Leo, he is known for his dedicated and analytical nature, qualities that have served him well in his professional career.