SEPTEMBER. Annual summer celebration at Twin Lakes Park near Greensburg, Pennsylvania. Fiber Events Calendar. Watch for him! About; Visit; Participate; Archives: Schedule There are also special events held thru out the year. All Pennsylvania Cities; Explore Another City; . In August, an estimated 50,000 people attend the Washington County Fair. Washington County Featured Events. Event is presented by the New Cumberland Olde Towne Association. - Manage notification subscriptions, save form progress and more. MN. The crown jewel of the Washington County Fairgrounds, the Event Center opened in the Fall of 2002 to provide a first rate venue for wedding receptions, anniversary celebrations and other social events.. The Washington County Fairgrounds is located a couple miles north of Washington, PA in Chartiers Township, making it convenient to a variety of events held in Washington. April. Washington, PA,