Director Jim Mickle was influenced by Il duro del Road House (1989) and the Korean drama Memorie di un assassino (2003). After exploring feminist themes in We Are What We Are (2013), Mickle wanted to explore more masculine themes in 'Cold in July'. He called 'Cold in July' "the other side of the coin" to 'We Are What We Are' and a film about being "sucked into your own kind of action movie." Mickle tried to work in many 1980s themes and references to John Carpenter's work from that period.
Michael C. Hall and Vinessa Shaw's characters can be heard watching an episode of the short-lived TV series The Master (1984) (aka Master Ninja) on their living room television. Lee Van Cleef's character can be heard talking to the bartender.
The score was composed by Jeff Grace. Director Jim Mickle and Grace had collaborated on several films previously, and they had earlier planned what kind of score they wanted for 'Cold in July'. It was influenced by John Carpenter's scores.
Joe R. Lansdale said that he saw all the revisions of the script except for the last and "felt respected through the entire process."
Jim Mickle stated that he had difficulty getting the film made. It took seven years from when he first read the novel. The first draft of the script, a verbatim copy of the novel, was 220 pages long; from there, Mickle and Nick Damici edited the script down to a more manageable size. The final script was also the furthest from the novel, but they felt it was closest in spirit.