Trivia

Though credited as producer, John Carpenter described his involvement in this way: "I come in and say hello to everybody. Go home."

Selma Blair did almost all of her own stunts. For her underwater scenes, she spent 12 hours in a water tank, with only short surface breaks, for two days straight.

Tom Welling's character, Nick Castle, is named after Nick Castle, the actor who played The Shape in John Carpenter's Halloween (1978).

In between takes in Vancouver, press were granted access to the set. During Selma Blair's interview, director Rupert Wainwright made a joke she didn't like. In response, Blair reached into her shirt, pulled out a rubber breast enhancement pad, and flung it across the conference room at the director, deadpanning, "That's the Adrienne Barbeau part of the role."

Tom Welling had three weeks left on Smallville (2001) season 4 when he began shooting this film. Selma Blair often joked that the director kept two cameras running during his scenes, one for 'The Fog', and one for 'Smallville'.