A dryer appliance and a method of operating the same are provided. In one aspect, the dryer appliance includes a drum rotatably mounted within a cabinet. The drum defines a chamber that is in fluid communication with a conditioning system of the dryer appliance. The conditioning system heats air circulating therethrough. A variable speed blower fan is provided to circulate air between the conditioning system and the chamber. A sensor is positioned at or proximate a drum exit of the drum. A controller of the dryer appliance receives an input indicative of the relative humidity of the air at the drum exit. Based on the received input, the controller determines a control command. The control command can be routed to a blower fan motor operable to drive the blower fan. The blower fan motor receives the control command and adjusts a flow rate of the air exiting the drum exit.