Abstract: Disclosed in a Rainfall Detection and Disable Control System which provides detection and a visual display of both a trace level and a variable accumulation level of natural rainfall. The dual interacting rainfall detection system provides a unique sprinkler system control function that disables sprinkler system watering both during and after a rain shower, based upon the amount of rainfall accumulation, and user selectable disable time periods. A short variable disable time period is initiated by the trace rainfall detection probe and a long variable time period is initiated by the accumulation rainfall detection probe. The trace rainfall detection probe provides the control function of preventing watering, at the onset of, and during a rain shower. The short disable time period of the trace detection function allows the next watering cycle to occur, if no significant rainfall accumulation is detected.