A method is provided for monitoring an operational parameter of a wind turbine. The method comprising defining a peer limit, measuring the operational parameter during operation of the wind turbine; and comparing the measured operational parameter to the peer limit. The wind turbine is a member of a peer group of wind turbines, each wind turbine of the peer group comprising a common characteristic. The peer limit is defined using measurements of the operational parameter measured on the wind turbines of the peer group of wind turbines.