Disney rarely cancels fireworks in advance, but if a show is called off due to inclement weather or technical issues, they will notify guests through several channels. The primary method is via overhead public address announcements throughout the park; these are usually made 15 to 30 minutes before the scheduled start time. You should also check the My Disney Experience app (for Florida) or the Disneyland App (for California), where the status of the show will be updated from a specific time to "Temporarily Closed" or "Cancelled." Additionally, Disney cast members stationed around the hub and the castle will be informed via radio and can provide real-time updates to guests. High winds are the most common reason for cancellation, even if it is not raining, as pyrotechnic debris can become a fire hazard. If a show is delayed, Disney will often announce a "weather hold" in hopes of performing the show 15 or 30 minutes later. If the fireworks are cancelled entirely, Disney sometimes still performs the projection-only version of the show on the castle so that guests still get some form of nighttime entertainment.