Abstract: A weather monitor and irrigation override system for use with an irrigation control system. In a preferred embodiment, the weather monitor and irrigation override system comprises a controller transceiver couplable to an irrigation control system, an environmental sensor, a sensor transceiver coupled to the environmental sensor and configured to wirelessly and bi-directionally communicate with the controller transceiver, and a system identifier module coupled to the controller transceiver having a communications identifier unique to the sensor transceiver and the controller transceiver whereby the controller transceiver accepts wireless transmissions only from the sensor transceiver. A method of manufacturing the weather monitor and irrigation override system is also provided.