In my 4-5 years of EV ownership, I have fried some plugs & receptacles from rainy conditions and have been shocked a few times. Also, a bit of misplaced moisture can cause the circuit to trip leaving you without a charged up car.
To fix this, I have purchased from Fruit Ridge Tools
www.fruitridgetools.com) both a Leviton WETGUARD male & female plug. Both have a nice bright yellow rubber housing with yellow rubber sleeves to lock out water. The female connector comes with an attached cap that covers the receptical when not in use. I really like the quality of the product.
I ordered (through Ebay) the connectors on a Tuesday afternoon. They shipped the same day and arrived on Thursday's mail. Both parts together cost $29.90 plus $6.43 for shipping & handling. I ordered NEMA 6-20, 250V connectors. Other flavors are available.
If you drive an EV and don't use a fancy J1772 connector, I highly recommend going with a waterproof connector.