The CamelBak backpacks are not waterproof per se, but given their high standards and quality, the backpacks are not vulnerable to a little bit of rain. However, in case of heavy rain, there is every chance that the water will seep in and cause damage. Luckily there is an easy solution for this. You can buy the CamelBak rain cover which will insulate your backpack and the items inside it from the rain.