Though the official end of summer doesn't arrive for weeks, Labor Day serves as the mournful marker that pool parties, water park outings and picnics in the garden are about to slide off your social calendar. This weekend, take advantage of several popular summer events set to pack it in for the season.

The Jazz in the Garden Friday soirees bring out hundreds of picnickers for a night of music amid sculptures by Claes Oldenburg and Joan Miro. The free concerts that began Memorial Day weekend end Friday with a blowout featuring violinist Bruno Nasta and
the U.S. Navy Commodores Jazz Ensemble, Friday from 5 to 8:30 p.m. at the National Gallery of Art Sculpture Garden.

A cooler-than-usual summer has knocked visits to the pool from the top of our priority list. If you were hoping to splash at all this summer, this holiday weekend provides your last chance. Several pools closed as schools reopened, and the remainder of the area's outdoor pools and spraygrounds will close Monday; check your county's parks and recreation Web site for hours. One welcome exception: The District's East Potomac Park pool isn't scheduled to close until Oct. 13.

Also shuttering in coming weeks is a seasonal rooftop bar that became a social-scene staple this summer. DNV, on the rooftop of the Donovan House Hotel near Logan Circle, opened Memorial Day weekend with innovative offerings including a Pimm's Cup on tap. Guests get use of the pool and roof during the day, but after 5 p.m. on weekdays and 7 p.m. on weekends, it's wide open to revelers. The rooftop lounge closes for the season Monday (barring bad weather, of course). Update: DNV says it will keep the lounge open till the weather becomes too cool to stay open.

Some concert schedules were abbreviated this year as national parks faced automatic spending cuts, but one big event remains at Carter Barron Amphitheatre. The DC Blues Festival, in its 25th year, serves as the final outdoor concert of the season at the Northwest Washington venue. Gates open at noon Saturday.

The National Building Museum's duo of nine-hole mini-golf courses are indoor, architect-created, high-design playgrounds with local themes, glowing lights and plenty of interactive elements. The second summer of this cool, kid-friendly event ($5 per course per person) closes with Monday's rounds. Open during museum hours at National Building Museum.

Fans of the Hill Country Backyard Barbecue pop-ups at the Building Museum get an extension. The free outdoor parties, which feel like a honky-tonk version of Jazz in the Garden thanks to a hay bales, conclude Sept. 14 with a day-long bash featuring plenty of Shiner, barbecue and a performance by Brooklyn-born fuzz rockers Crushed Out. Until then, music continues at the barbecues Thursdays through Saturdays from 5:30 to 8:30 p.m.

Follow Lavanya Ramanathan on Twitter at @lalamasala and on Instagram at lavanyarama.