McLain was born and raised in Chicago where, as a kid, he watched his hero Harry Volkman on television. Volkman is known for being the first weatherman to issue a tornado warning. McLain is remembered for making swooping gestures while talking about weather fronts. McLain majored in meteorology and minored in Radio/TV at the University of Wisconsin in Madison where he did a weekly weather program on the campus TV station. Graduating in 1967, he became a weather officer in the Navy. His first TV weather job was at WKZO, Kalamazoo, Michigan. And in May, 1972, he became a TV meteorologist at WFBM-TV, (WRTV), Channel 6, staying until 2002.