Moisture entering an outdoor outlet can create a shock or fire hazard.
A cover that closes over an empty outlet may not protect it while a cord is plugged in. Wet-weather use needs a cover designed to protect the connection while in use.
Indoor extension cords are not designed to withstand outdoor moisture, temperature changes, and wear.
Keep covers closed on unused outdoor outlets. Ask an electrician to replace damaged covers and provide weatherproof protection while cords are plugged in.
Use GFCI-protected outdoor outlets. If you are unsure whether yours are protected, have an electrician check before connecting outdoor equipment.
Choose extension cords marked for outdoor use, and avoid using corded electric tools in wet or damp areas.