New seasons of "Castle" usually begin in the month of September, as of 2015. Although the first season of the show aired in March, the following six seasons have all debuted at the end of September.
"Castle" is an American crime drama broadcast on ABC starring Nathan Fillion as Richard Castle and Stana Katic as Kate Beckett. Castle, a best-selling mystery writer, is paired with Beckett, a homicide detective, to solve various crimes across New York. The plot typically hinges on the crime mysteries and the relationship between Castle and Beckett.
The show premiered in 2009, and its seventh season premiered in 2104. The rank and number of viewers has continued to rise with each new season.