Yes it is, my friend. It is absolutely water and dust proof. It has an IP (Industrial protection) rating of 67. Which happens to be one of the higher ones, it is up there with Galaxy Note 8. It can survive in a one meter deep water for up to 30 minutes. You can basically have a shower with it, although i wouldn't risk it, i don't like playing with such an expensive toy
I'd just like to point out that it is never a good idea to expose your phone to water even if it is water resistant (no phone is truly waterproof). In some occasions the manufacturer might refuse to have your phone repaired if it suffered water damage. I remember Sony doing this.