A display may have an array of pixels. The display may be controlled using display driver circuitry. The display driver circuitry may analyze image data to be displayed on the array. When static content is detected, the rate at which the pixels are refreshed may be adjusted to conserve power. If a static image is detected, the gate lines may be asserted at a lower refresh rate than if moving content is detected. To avoid visible artifacts, the display driver circuitry may use temporal and spatial refresh rate buffers. Temporal buffers ensure that refresh rates are changed gradually as a function of time, thereby minimizing flicker. Spatial refresh rate buffers are used to provide a smooth transition between low refresh rate and high refresh rate regions in a display as a function of position.