A flowmeter determines the flow direction of a fluid. The flowmeter has a measuring element, around which the fluid flows and which comprises at least one fiber-optic cable and at least two electrical heating elements that lie adjacent to the fiber-optic cable(s) by a respective heat stream emanating from the respective heating element and directed towards at least one fiber-optic cable, the directions of the heat streams being at least proportionately reversed. In addition, the values of the individual heat streams can be influenced to different extents, depending on the flow direction of the fluid. An electromagnetic wave that can be coupled into the fiber-optic cable(s) can also be influenced according to the temperature of the fiber-optic cable(s). Additionally, the flow meter has a control unit, which is used to feed electric energy to the two or more heating elements one after the other, and an evaluation unit, which is used to evaluate the temperature effect of the electromagnetic wave that emanates from the individual heat streams and to determine the flow directed of the fluid.