If it's September, it must be time for the annual neighborhood festival shifts into high gear Sunday along Columbia Road, between 18th and 19th streets NW, from noon until 10. There'll be 250 booths selling all sorts of ethnic food, arts, crafts, causes and concerns, plus an art show, live music all day and night from more than 15 bands and lots of singing and dancing in the street. Some of the performers include: the Jan Taylor dance theater, Video Buddies, Sweet Honey in the Rock, Tex Rubinowitz, Tom Principato and the Dynettes. Parking is limited, so you might want to take Metrorail's Red Line and exit at either Dupont Circle or the Woodley Park/National Zoo station and walk over. Call 462-5113; free.

The TAKOMA PARK FOLK FESTIVAL is Sunday, too, offering still more food and music for weekend party-goers on the grounds of Takoma Park Junior High School from 11 to 7. Saxophonist Ron Holloway will be there and so will Loose Fish, the Footloose Cloggers and the Rock Creek Morris Dance Team. The school is at 7611 Piney Branch Road -- three long blocks from the Takoma Park Metro station. If it rains, all activities will move inside the school. Call 829-8802; free.

If you don't want to wait until Sunday to be festive, the Hare Krishnas are having a SATHAYATRA FESTIVAL (festival of the chariots) on the grounds of the Washington Monument at 14th and Constitution Avenue NW on Saturday. At noon, three 50-foot chariots, weighing about five tons each, will be pulled along the Mall to the Capitol and back to the monument grounds where a free vegetarian meal, East Indian music and art and ox-cart rides will await paraders. The festival will continue on Sunday -- same time, same place. Call 544-3377.