4 ways to celebrate Harry Potter — 20 years after the series launched in the U.S.

July 31 is always a big day for Harry Potter fans. The character and his creator, British author J.K. Rowling, share a July 31 birthday that is celebrated in bookstores and fan sites worldwide.

September 2018 also marks the 20th anniversary of the U.S. publication of “Harry Potter and the Sorcerer’s Stone.” Stores including mega-retailer Target are celebrating with a large stock of Hogwarts clothing, along with anniversary edition books and gift sets. Here’s a roundup of ways Harry Potter fans can get in on the fun.

1. Harry Potter’s Birthday Party (July 28). The third annual event at Changing Hands bookstore in Phoenix includes a 5-7 p.m. celebration for kids and an 8-11 p.m. party for adults with a Defense Against the Dark Arts theme. There’s also a 2 p.m. party at Changing Hands in Tempe. Costumes are encouraged! Plus: Butterbeer, Polyjuice Potion and more.

2. Summer Reading: Harry Potter! (July 28). Desert Sage Library in Phoenix hosts an all-ages end-of-the-summer reading party from 1-3 p.m.

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3. New anniversary books. You’ll notice new Harry Potter books in stores with 20th anniversary covers, illustrated by none other than Caldecott Medalist Brian Selznick. If you haven’t looked at Harry Potter books in awhile, you’ll be pleased to find new illustrated editions, plus fun supplements, such as “Marauder’s Map Guide to Hogwarts,” with a wand that reveals secrets on the fold-out map at your favorite local bookstore.

RELATED: Noteworthy kids books by Brian Selznick

4. “The Wizarding World of Harry Potter” opened at Universal Studios Hollywood in 2016, featuring high-tech rides and an impressively detailed Hogwarts castle. Potter fans can wander through the snow-capped roofs and bustling cobblestone streets of Hogsmeade, sit in a cabin of the Hogwarts Express and explore the rooms and halls of the School of Witchcraft and Wizardry.

In the heart of Hogwarts castle is “Harry Potter and the Forbidden Journey,” a ride that takes guests sporting 3D goggles into a high-flying Quidditch match. At “Flight of the Hippogriff,” Universal Studios Hollywood’s first outdoor coaster, guests wind through the Care of Magical Creatures grounds and Hagrid’s pumpkin patch and past his cottage before climbing aboard two-seat wicker baskets for a “training flight.”

You can also shop and eat like Potter and his friends. Three Broomsticks tavern features shepherd’s pie, fish and chips and Butterbeer. At Ollivanders shop, where the wand chooses the wizard, you’ll find magic wands that trigger interactive window displays throughout the park. If you go: 100 Universal City Plaza, Universal City, Calif. $90 and up daily; $119 annual pass. universalstudioshollywood.com