A method has been developed for determining the magnitude and direction of an unknown velocity vector utilizing two-dimensional thermal anemometry. Unlike most thermal anemometry procedures, the analysis accounts for the velocity component parallel to the sensing element. The method requires determination or calibration of the flow constants at only two flow orientations: perpendicular to each sensing element. A comparison of the analysis to calibrated nozzle flow data showed good agreement for both the flow angle and velocity magnitude within the range of applicability. This type of thermal anemometry will be used to help characterize flows in and around optical access ports. 2 refs., 1 fig., 1 tab.