A rain sensor can be configured to shut off one or more irrigation devices during and/or after a period of rainfall. The rain sensor can include a moisture basin mounted therein. The moisture basin houses an absorbent element configured to expand in at least one direction when wetted. Expansion of the absorbent element can activate a signal actuator to generate a shut off signal to one or more irrigation devices. The moisture basin can retain excess moisture when the absorbent element is fully saturated.
