The Jazz Loft, 275 Christian Ave., Stony Brook continues its annual Harbor Jazz Festival tonight at 7 p.m. with the Mike LeDonne Organ Trio (see website for prices); the Vijay Iyer Trio on Sept. 18 (see website for prices); and a free outdoor festival on Sept. 19 on the Stony Brook Village Green at noon, 1 p.m., 4 p.m. and 7 p.m. and on the Jazz Loft Lawn at 3 p.m. and 6 p.m. www.thejazzloft.org

The Long Island Museum, 1200 Route 25A, Stony Brook invites the community to a free lecture, Long Island and the Legacy of Eugenics, with author Mark Torres from 7 p.m. to 8:30 p.m. Torres will discuss the dark history of the eugenics program developed by the Eugenics Record Office at Cold Spring Harbor during the early 20th century. Followed by a book signing. 631-751-0077

St. Paraskevi Greek Orthodox Shrine Church, 1 Shrine Place, Greenlawn invites the community to its annual Greek Festival tonight from 6 to 10 p.m., Sept. 19 and Sept. 20 from 11 a.m. to 11 p.m. Enjoy authentic Greek food and pastries, rides and games. 631-261-7272, www.stparaskevi.org

The Reboli Center for Art and History, 64 Main St., Stony Brook continues its Third Friday series with a lecture by Patrice Domeischel titled Four Harbors Audubon Society and Our Local Nature at 6:30 p.m. Free. No registration required. 631-751-7707

Huntington Historical Society presents a lecture on Nathan Hale at the Conklin Barn, 2 High St., Huntington from 7 p.m. to 8:30 p.m. Nathan Hale can be considered many things: a hero, a martyr, a failed spy.But mostly he is a mystery. Join Toby Kissam and Town Historian Robert Hughes for a presentation on the many theories about Nathan Hale. Tickets are $15, $10 members. Register at www.huntingtonhistoricalsociety.org.

The 12th annual Port Jefferson Dragon Boat Race Festival heads to Harborfront Park, 101 East Broadway, Port Jefferson from 8:30 a.m. to 5 p.m. Presented by the Greater Port Jefferson Chamber of Commerce, the event will showcase dragon boat races throughout the day with Asian-themed food, cultural crafts, traditional lion dance, vendors, children activities and much more. Held rain or shine. Free admission. 631-473-1414, portjeffdragonboatracefest.com