An intelligent irrigation rain sensor for use in an irrigation system comprises a rain sensor unit and a sensor control unit. The rain sensor unit has a rain catcher reservoir with an open top for receiving rainwater with an internal volume for holding water and tapers into a funnel. At least one droplet detector is positioned directly below the funnel opening that contacts the water droplets from the funnel. The droplet detector includes detection electrodes for sensing a change in an electrical property being monitored by a detection control in the sensor control unit and for discriminating phantom droplets from rain. Upon exceeding a rain threshold amount over measurement time period, the intelligent irrigation rain sensor issues a rain signal to the irrigation controller. The intelligent irrigation rain sensor issues a corresponding dry signal to the irrigation controller after a drying period has elapsed.