Our upcoming trip in August 2017 will be our first time visiting Disney/Universal in August. We want to go to Volcano Bay on 8/21, and purchase tickets and express pass, as we believe that the express pass will sell out fairly quickly. However, I am considering that with the unpredictable weather that it may be a bad idea to commit to visiting on this day, as there is a possibility that the forecast may say that it will rain all day. Does this happen frequently in August where it rains all day/where we would not enjoy visiting a water park? Please let me know your thoughts!