A system and method for dithering a clock signal during idle times is disclosed. An integrated circuit (IC) includes a number of functional units and a clock tree. The clock tree includes a root level clock-gating circuit, a number of regional clock-gating circuits, and a number of leaf level clock-gating circuits. The root level clock-gating circuit is coupled to distribute an operating clock signal to the regional clock-gating circuits, while the regional clock-gating circuits are each configured to distribute the operating clock signal to correspondingly coupled ones of the leaf level clock-gating circuits. The IC may further include a control unit configured to monitor activity levels and indications from each of the functional units. The control unit may cause the root clock-gating circuit to dither the clock signal if the IC is idle, wherein dithering includes reducing the duty cycle and the effective frequency of the operating clock signal.