The level of water resistance in ATV storage boxes or racks can vary depending on the specific product and its design. While some storage boxes may offer a higher degree of water resistance, it's important to note that most ATV storage solutions are not entirely waterproof. They may provide some degree of protection against light rain or splashes, but they may not be completely sealed against heavy downpours or submersion. If you need to protect your items from water damage, consider using additional measures such as waterproof covers or bags for added protection.