2005 | 8 Episodes

Season 1 of Spiral premiered on December 13, 2005.

2008 | 8 Episodes

Season 2 of Spiral premiered on May 12, 2008.

2010 | 12 Episodes

Season 3 of Spiral premiered on May 3, 2010.

2012 | 12 Episodes

Season 4 of Spiral premiered on September 3, 2012.

2014 | 12 Episodes

Season 5 of Spiral premiered on November 10, 2014.

2017 | 12 Episodes

Season 6 of Spiral premiered on September 18, 2017.

2019 | 12 Episodes

Season 7 of Spiral premiered on February 4, 2019.

2020 | 10 Episodes

Season 8 of Spiral premiered on September 7, 2020.