A sensor system is provided for determining at least one parameter of a fluid medium flowing through a channel, in particular an intake air mass flow of an internal combustion engine. The sensor system includes a sensor housing, in particular a plug-in sensor which is introduced or is introducible into a flow tube, in which the channel is formed, and at least one sensor chip which is situated in the channel for determining the parameter of the fluid medium. The sensor housing has an inlet into the channel which points counter to a main flow direction of the fluid medium, and at least one outlet from the channel in a surface of the sensor housing. The surface of the sensor housing has multiple recesses upstream from the outlet viewed in the main flow direction.