NEW YORK—Once upon a time, Halloween was a one-day event. Then the pumpkins and parties started moving back to the weeks between Columbus Day and Oct. 31.Now the holiday is morphing into an entire season, at least in the tourism industry, with haunted walks, costume balls and pumpkin-carving events held throughout October. Some even start in early September, like Mickey’s Not So Scary Halloween Party at Disney World, which starts Sept. 5—just four days after Labor Day, http://www.wdwinfo.com/holidays/halloween.htm. In 2004, the same event at Disney World started Oct. 1.

The Illinois Bureau of Tourism has gone so far as to trademark the term “Fall-O-Ween” to describe what it calls the state’s “distinctive fifth season.” Events range from the Morton Pumpkin Festival, Sept. 10-13, to Six Flags Great America’s “Fright Fest,” which starts Oct. 4, to the St. Charles Scarecrow Festival, Oct. 10-12. A Web site highlighting three-day getaways in Illinois for the season launches Sept. 8 at http://www.enjoyillinois.com/3-day.

“The fall season in Illinois is packed with events that attract a wide range of visitors, and those incorporating a spooky, Halloween element are always popular,” said Jan Kostner, deputy director of the Illinois Bureau of Tourism. “Fall-O-Ween encompasses all of those great events and attractions that truly represent theessence of autumn.”

Salem, Mass., which has the most authentic claim on witchy whoopla of just about any destination in the country, started a Halloween celebration 27 years ago as a one-day event for children. Now the city where witch trials were held in 1692 holds Salem Haunted Happenings from Oct. 2 to Nov. 2—http://www.hauntedhappenings.org—and gets 30 percent of its annual tourist visitation in that one month.

“It is our busiest season,” said Kate Fox, executive director of Destination Salem. Highlights include a costume parade of thousands of children, Oct. 2; a costume ball at the Hawthorne Hotel, Oct. 31; “Festival of the Dead” nighttime parties geared to adults and Harry Potter-themed daytime events for kids. At the House of the Seven Gables mansion and historic site, there are tours and dramatic presentations about the families who inspired Nathaniel Hawthorne’s famous novel.

In Ohio, the Cedar Point amusement park’s “HalloWeekends” run weekends from Sept. 12-Nov. 2 with a parade, a new fun house for little ones and outdoor walk-through attractions, http://www.halloweekends.com.