The invention provides a regulator system for regulating the operation of an irrigation system which is responsive to user programmed information. It has a control element for issuing watering control signals to an irrigation system, having at least one of (i) a duration programming device for programming a minimum amount of time and a maximum amount of time for the suspension of watering by the irrigation system, and (ii) a user adjustable temperature programming device for programming a minimum allowed temperature for initiating a watering period by the irrigation system. It further has an irrigation system interface for connecting said control element with the irrigation system. It also has a switch for conveying the control signals from the control element to the irrigation system via the irrigation system interface, for either permitting or prohibiting watering by the irrigation system, responsive to the control signals generated by and received from the control element.