Methods and apparatus are provided herein for permitting or interrupting irrigation using sensor equipment. In one embodiment, a method for controlling irrigation comprising the steps of: generating an indication representing the amount of rain fall at a sensor unit; transmitting a signal comprising at least the indication from the sensor unit to an interface unit, wherein the interface unit is adapted to cause an interruption of programmed watering schedules of an irrigation controller; receiving the signal at the interface unit; determining, based at least on the indication from the signal, whether irrigation should be interrupted; and generating an interrupt command to interrupt irrigation.