A gas cooktop defining includes a gas burner for selectively generating a flow of heated air, a grate positioned over the gas burner, and a griddle assembly seated on the grate over the gas burner, the griddle assembly comprising a griddle defining an outer side and a probe receptacle defined in the outer side, a temperature probe configured for receipt within the probe receptacle, and one or more flow control features for directing the flow of heated air around or away from the probe receptacle.