A rectal thermal monitor for transrectal prostate temperature measurement includes a handle arranged in a proximal end portion of the monitor for gripping by a user, an elongate shaft extending from the handle, and a probe portion arranged on a distal end portion of the shaft. The probe portion is arranged at a position opposite the handle portion, and is shaped to facilitate insertion through an anal sphincter and into a rectum of a patient. A temperature sensing element is arranged within the distal probe portion and is adapted and configured to sense a temperature of the prostate of the patient through the rectum wall of the patient. The probe portion can include one or more compliant materials and/or be shaped so as to compress during insertion through the anal sphincter of the patient.