The outdoor portion of an A/C system is built to withstand the rain, and even severe rainfall will not damage it. The answer is: Yes, you can use these systems, even during heavy rain. Keep your systems in good working order and the rain will not damage them.
Do you need to cover your AC unit when it rains?
In most cases, the condenser unit should never be covered. Rain cannot harm the condenser, as long as the moisture can evaporate freely, and neither can the cooler weather of a Florida winter. Otherwise, simply keep the condenser free of debris, and rinse the dirt out periodically.
Can AC units be rained on?
Even though heavy rains cannot damage your AC unit, the winds accompanied by the same rain can leave dirt, leaves, twigs, and other debris to damage the condenser fan grille. Many homeowners prefer to cover their AC units for the winter if their internal parts are exposed.