According to SFGate, aloe vera plants need water only when their soil completely dries out. Aloe vera can do well in dry, desert conditions, as the plants store water in their leaves.
When the soil completely dries out in the aloe pot, owners must water the plant until the water drips from the bottom of the pot. They must then wait to water the plant again until the soil is dry. For aloe vera in an outdoor setting, rainwater is typically all it needs to thrive, but in high-desert and drought conditions, it's best to water until the top six inches of soil are moist.