I believe most of the lights retailed in stores have a water resistant feature. Water resistant means they can withstand splashes and rain. Water proof, on the other hand means you can submerge it in water to a certain depth. Either way, you'll be fine with a MiNewt. I used one for ages and it never faulted me in any sort of hot nights, muddy rides or rain soaked adventures but you may want to look at some sort of covering for the plug that fits into your battery, that me be the only spot that may corrode over time. Maybe plug the lead into the battery then tape a plastic bag over it?