While Islanders of all ages and towns are picking up a wide variety of books before hitting the beach this summer, booksellers and librarians echo that there’s one identifier that clearly shows distinction in taste: a reader’s gender.

“Men read thrillers and nonfiction. Women read fiction across the board,” said Irene Tewksbury, assistant librarian at the Chilmark Library.

Gender aside, the most requested book at Vineyard libraries and purchased at Island bookstores this summer is The Perfect Couple by Elin Hilderbrand, a prolific and popular Nantucket-based author of sun-soaked thrillers often featuring Cape and Islands characters.

“We can hardly keep it in the store,” said Mathew Tombers, a bookseller at Edgartown Books. He added that their first dozen copies were gone in under 24 hours and the store has to put in a weekly reorder for new copies to keep up with demand.

Andrea Figaratto, Oak Bluffs Library head of circulation, said that she wasn’t surprised at The Perfect Couple’s popularity. She said the book, and the beach fiction genre as a whole, were practically designed to be read with toes in the sand.

“When you look at the book you can see Adirondack chairs and blue skies, and they’re all about short summer friendships and romances,” she said.

Ms. Hilderbrand may be the queen of summer fiction year after year, but hold lists provided by Island librarians showing their top requested books this summer span a cornucopia of genres, settings and subject matter.

Coming in at number two on the list, and number one for nonfiction, is a book about an Idaho girl who leaves her survivalist family to get a formal education. Educated by Tara Westover was one of the few books to appear on the most requested lists for each of the six Island libraries.

Mr. Tombers said it’s been one of the easiest books to sell because he doesn’t have to do much convincing as other bookstore patrons do it for him.

“I’ve had people pick it up and people will tell them to buy it,” he said. “It’s arguably the best book I’ve read in my life.”

Other notable entries on the most requested list are a political thriller co-written by a living president (The President Is Missing by Bill Clinton and James Patterson), unreliable female narrators in the style of Gone Girl (The Woman in the Window, The Woman in Cabin 10), and an acerbic take on suburbia (When Life Gives you Lululemons). Stephen King has also surged in popularity this year, according to several librarians, despite the dark subject matter of his horror fiction.

Many factors play into how certain books become the talk of the town while others get edged out of bookstore displays. For most of the Vineyard’s most-wanted this year, Island librarians point to a printout of the New York Times Bestseller list on their checkout counters. Compared to the Island list, the two are very similar — The Perfect Couple is number five in hardcover fiction five weeks after release. Educated is still number two in nonfiction, 22 weeks after release.

“If a book hits the New York Times list then it circulates here,” said Chilmark library director Ebba Hierta. She added that she believes Islanders have a more discerning literary palate than bookworms on the mainland.

A little Vineyard flavor is also a recipe for success on-Island, especially if the author is making an appearance at various events here. The most popular example is How to Change Your Mind by Michael Pollan, a nonfiction exploration into altered states of consciousness. Mr. Pollan, an Aquinnah summer resident, will give a talk about the new book at the Chilmark Community Center on Sunday, Aug. 19 as part of the Author Series.

“When you hear authors speak about books it inspires you,” said Bill Schreiber as he perused the Author Series list of events in Bunch of Grapes. An American Marriage by Tayari Jones, who will speak on August 16, was displayed prominently and embossed with a seal of Oprah Winfrey’s Book Club approval.

Though the top-requested books are similar, a tour of Island libraries also shows patterns based on the culture of each town. Beach-reads and James Patterson lead down-Island towns, while cookbooks and food-health titles such as the Plant Paradox and Food: What the Heck Should I Eat are common selections up-Island in West Tisbury and Chilmark.

In Aquinnah, home of the Wampanoag Tribe of Gay Head (Aquinnah), a novel written by Tommy Orange, a Native American author, called There, There tops the hold list. The debut novel follows a group of urban Native Americans living in Oakland as they convene for the big powwow in Oakland.

Children and young adults are also scheduling reading into their summer breaks. Rizwan Malik, assistant director and youth services librarian at the Chilmark Library, said that fantasy and dystopia remain the favorites of the teenage crowd, though grounded dramas set in the real world are also in demand.

“Kids are checking out realistic fiction where they can see themselves as the main characters,” said Mr. Malik, pointing to books by John Green in particular. Mr. Green, who’s newest book Turtles All the Way Down was published last year, is acclaimed for writing young-adult fiction with main characters suffering from mental illness.

Mr. Malik said that he doesn’t remove books from the young-adult shelf unless they haven’t circulated for three years. All of Mr. Green’s books are displayed, covers facing out next to familiar epics like The Chronicles of Narnia and The Hunger Games.

At the Oak Bluffs library, summer reading program coordinator Carolina Cooney agreed that children and young adults are picking up books with heavier themes. One example is Simon vs. the Homo Sapiens Agenda, recently adapted into the movie Love, Simon, a coming-of-age story featuring a closeted gay high-schooler.

“They are gearing more toward inclusive books with diverse characters,” she said.

Whether curled into a reading nook, splayed out on the sand or listening to an audiobook while waiting in the ferry line, it’s not hard to find an Islander reading on a sunny summer day. On a recent afternoon in Edgartown, Curt Carlson sat on a park bench along Main street reading Twisted Prey by John Sandford, the 28th installment in the crime series.

“I don’t read much fiction, only crime fiction,” Mr. Carlson said. “Guess I’m just a typical male reader.”