On August 16, 1940, Hurley was appointed the sixth Bishop of St. Augustine, Florida, by Pope Pius XII. It was believed by some that his appointment was made in order for him to remain in contact with the ailing Myron Charles Taylor, the American emissary to the Vatican. Others believed the appointment was a punishment; Hurley had become a critic of the wartime policy of the Vatican, believing Pope Pius XII was overly fearful about communism and not fearful enough about Nazism. He received his episcopal consecration on the following October 6 from Cardinal Luigi Maglione, with Archbishops Celso Costantini and Clemente Micara serving as co-consecrators, at the chapel of the Pontifical Urbaniana University in Rome. Returning to the United States, he was installed as Bishop of St. Augustine on November 26 of that year. The bishop was instrumental in building up the Diocese, which encompassed all of Florida at the time. Bishop Hurley, according to one retired priest, would fly around the state and locate property where the several new interstates were being planned. Hurley would buy up the properties to established church parishes for the future. His vision allowed the Catholic Church to grow rapidly throughout the years.