Hi there Matalynn,
Welcome to planDisney and thank you for your question! I'm happy to hear that you'll be planning a trip to the Disneyland Resort in September - that is such a great time to visit the Happiest Place on Earth!
Typically, the best place to see the official schedule of entertainment and park hours is the
Hours & Events Calendar on the Disneyland Resort website. The schedule is available about six weeks out from the current date, which means that those first few weeks of September will be available in late July.
Currently, the schedule runs through late July and I do see
Fantasmic! showings throughout the month. However, when you visit in September, the
Halloween season will be in full swing, and the details of the nighttime spectaculars have not been officially announced yet.
My suggestion would be to keep an eye on the Hours & Events Calendar and the
Disney Parks Blog to get the details of all the fun things you'll get to enjoy during your upcoming trip.
Thank you again for your question, Matalynn! I hope you have a wonderful time at the Happiest Place on Earth this fall.
Have a Magical Day,
Greg