Systems, devices and methods of determining orientation of a distal end of a medical instrument (e.g., electrode-tissue orientation of an RF ablation catheter) are described herein. One or more processors may be configured to receive temperature measurements from each of a plurality of temperature-measurement devices distributed along a length of the distal end of the medical instrument and determine the orientation from a group of two or more possible orientation options based on whether temperature measurement values or characteristics of temperature response determined from the temperature measurement values satisfy one or more orientation criteria.
