The visible sky is monitored by a set of cameras for contrails produced by a high-altitude aircraft. In response to identifying a contrail, the contrail is tracked across the field of view of the camera. Contrail data generated when the contrail is identified and during the tracking of the contrail is stored. The contrail data describes characteristics of the contrail including the spread of the contrail and the movement of the contrail across the field of view of the camera. Coordinates of the high-altitude aircraft are determined and compared with the contrail data to identify wind conditions.