Given that Garmin is a brand known for the quality of its products, it pays special attention to details such as weatherproofing its devices as well. For this reason, most GPS units meet the international IPX7 rating. This means that these models can be immersed in water for up to 30 minutes at around 40 inches (or 1 meter).
However, if you often ride in very rough weather conditions, you should check the device’s compatibility with this before making a purchase. Moreover, no matter what type of Garmin GPS unit you pick, you should make sure that it’s weather-resistant if you intend to use it often.
This way, you won’t have anything to worry about over time, and you will be able to rely on the unit for as long as necessary to make your investment worth it. So you shouldn’t hesitate to contact the manufacturer if you have any questions about this matter.