'America's Got Talent' season finale to air Sept. 18 with two-hour telecast

New winner to be named in live show from iconic Radio City Music Hall in New York

NBC has announced that "America's Got Talent," summer's No. 1 show in the 18-49 demo, will end its current season on Wednesday, Sept. 18, with a two-hour finale (9-11 p.m.).

"American Ninja Warrior" and "Siberia" will finish their respective current seasons on Monday, Sept. 16, with one-hour episodes.

Currently in its eighth season, "America's Got Talent" is averaging a 3.3 rating, 10 share in adults 18-49 and 12.2 million viewers overall with its Tuesday edition, making it the No. 1 summer series in the key 18-49 demo. "Talent" has been the No. 1 summer unscripted series in total viewers for each of its eight cycles to date. Every original telecast of "Talent" so far this summer has out-rated all entertainment competition in the time period on ABC, CBS, NBC and FOX in adults 18-49.

The live season finale, in which a champion will be named, is set to air from Radio City Music Hall in New York. Howard Stern, Howie Mandel, Heidi Klum and Mel B serve as judges with Nick Cannon as host.