Install weather and rain sensors for a more efficient irrigation system.
As simple as it gets. The sensor has a rain gauge and when it gets the adjusted amount of moisture it interrupts the common or turns off the timer until the water in the sensor gets below the set amount. The device is usually mounted on an eave on the building.
The modern sensor can detect freezing, high wind, excessive water flow, and moisture. These devices are often referred to as smart sensors.
Check and see if your water provider gives incentives for installing a weather or rain sensor.