Vortex flow sensor designed for measuring a flow velocity, a volume flow and/or a mass flow of a fluid flowing through a pipe, wherein said vortex flow sensor comprises: - a measuring tube inserted in the course of the pipe to conduct the flowing fluid, - a bluff body arranged in the interior channel of the measuring tube and serving to generate Karman vortices in the fluid, - a vortex sensor that reacts to pressure fluctuations generated by the vortices -- with a sensor vane that is located downstream from the bluff body, immerses into the flowing fluid and is moved by the vortices, particularly repeatedly, and -- with at least one sensor element which is mechanically coupled to the sensor vane and responds to movements of the sensor vane, as well as - a first temperature sensor and at least a second temperature sensor to measure temperatures in the flowing fluid, - wherein the two temperature sensors (34, 35) are arranged inside the sensor vane at a distance from one another and are inserted therein in such a way that they are not covered by the flowing fluid during operation, and - evaluation electronics to calculate the flow velocity, the volume flow or mass flow using the vortex signal supplied by the vortex sensor, wherein the evaluation electronics are designed to determine the temperature of the fluid using the temperature signals supplied by the temperature sensors (34, 35) in conjunction with mathematical models, which are saved in the evaluation electronics, for the transition of heat from the fluid to the sensor vane or heat dispersion processes within the sensor vane. - a measuring tube inserted in the course of the pipe to conduct the flowing fluid, - a bluff body arranged in the interior channel of the measuring tube and serving to generate Karman vortices in the fluid, - a vortex sensor that reacts to pressure fluctuations generated by the vortices -- with a sensor vane that is located downstream from the bluff body, immerses into the flowing fluid and is moved by the vortices, particularly repeatedly, and -- with at least one sensor element which is mechanically coupled to the sensor vane and responds to movements of the sensor vane, -- with a sensor vane that is located downstream from the bluff body, immerses into the flowing fluid and is moved by the vortices, particularly repeatedly, and -- with at least one sensor element which is mechanically coupled to the sensor vane and responds to movements of the sensor vane, - a first temperature sensor and at least a second temperature sensor to measure temperatures in the flowing fluid, - wherein the two temperature sensors (34, 35) are arranged inside the sensor vane at a distance from one another and are inserted therein in such a way that they are not covered by the flowing fluid during operation, and - evaluation electronics to calculate the flow velocity, the volume flow or mass flow using the vortex signal supplied by the vortex sensor, wherein the evaluation electronics are designed to determine the temperature of the fluid using the temperature signals supplied by the temperature sensors (34, 35) in conjunction with mathematical models, which are saved in the evaluation electronics, for the transition of heat from the fluid to the sensor vane or heat dispersion processes within the sensor vane.