Arnold was born on July 15, 1915, and he grew up in
Woodbridge, Connecticut, a town near
New Haven. During his childhood, he played hockey on ponds in rural Connecticut. Arnold then played on the high school hockey team at
Morristown School (now Morristown-Beard School) in
Morristown, New Jersey. During his four years at the school, Arnold earned recognition for his puck handling and smooth stride during hockey games. As a junior, he played on the 1933-1934 Morristown School hockey team that competed against teams from Europe during an overseas tour. Arnold also played on Morristown School's baseball, track, and cross country teams. He graduated from the school in 1935. In 1994, Morristown-Beard School inducted Arnold into the school's Athletic Hall of Fame. After high school, Arnold began his college studies in mathematics at
Bowdoin College in
Brunswick, Maine, and he continued his hockey career. In 1935, Arnold became the first freshman to make the men's varsity hockey team at Bowdoin. During his junior year,
The Boston Globe selected him for their All New England team. Arnold graduated from Bowdoin in 1939. As an alumnus, he continued to attend home and away games of the school's hockey team. In 1992, the school awarded Arnold a plaque to recognize his status as the Bowdoin Polar Bears' number one fan. Bowdoin awarded him the school's Polar Beard Award in 1999. The Polar Beard Award recognizes "significant personal contributions and outstanding dedication to Bowdoin" Arnold completed his master's degree in forestry at the
School of Forestry at
Yale University in 1941. During his studies at the school, he played on Senior hockey teams. The 1940 team performed well at the National Invitational Tournament in
Lake Placid, New York, and came close to winning the tournament. ==Military service during World War II==