She’s probably more alarmed about Screen on the Green ending than she should be. (Paramount Pictures)

There’s no surer sign of summer’s denouement than the conclusion of Screen on the Green: The apex of all outdoor movie screenings ends its four week run tonight at 8 p.m. with “Psycho.”

If you’ve been stalling, tonight’s your last, best chance to pack a picnic basket, grab some friends and settle in for a flick under the stars on the National Mall. Of course, there are other outdoor movie screenings that are still ongoing, but few, if any, can match Screen on the Green’s singular, only-in-D.C. pleasures.

Read more from the Going Out Guide:

Summer arts preview: best outdoor films

Best events for August and September

August’s best concerts