The film was originally titled The Night the Sun Came Out on Happy Hollow Lane, which was later shortened to The Night the Sun Came Out. As noted in a 21 Aug 1969 Los Angeles Sentinel news item, Mirror, Mirror temporarily served as a working title.
       On 7 May 1969, DV announced that John B. Bennett would produce the picture, with comedian Godfrey Cambridge attached to star, and Melvin Van Peebles on board to direct. The project marked Van Peebles’s second directorial effort after The Story of a Three Day Pass (1968, see entry). Godfrey Cambridge was set to appear in “whiteface” in certain scenes, and Var indicated it might be the first time such a performance would be captured on film. However, it was noted that actor Canada Lee had previously performed in whiteface in The Duchess of Malfi on Broadway (New York City, 15 Oct 1946). A 16 Sep 1969 DV brief stated that Cambridge had two body doubles on the film, one white and one Black. The actor and comedian planned to incorporate his experiences on set into a nightclub performance scheduled to take place at the Century Plaza in late Oct 1969.
       The casting of Cambridge’s co-star, Estelle Parsons, was announced in the 2 Jul 1969 DV. Principal photography began two months later on 4 Sep 1969, as stated in that day’s DV, with a beach scene filmed in Santa Monica, CA. Filmmakers had previously planned to shoot in Detroit, MI, on a $1-million budget, according to the 17 Sep 1969 DV. However, the budget went up to $1.25 million when it was decided that the entire picture could be filmed “at studio, ranch and Burbank locations.” Six minority trainees, five of whom were Black and one of whom was Japanese, were brought on as production assistant, soundman, cameraman, script supervisor and unit manager assistant, editor, and assistant director. Their salaries reportedly totaled $6,000, and an item in the 25 Sep 1969 Los Angeles Sentinel pointed to their hiring as proof of an increasing presence of Black Americans working as creative personnel, craftsmen, and technicians in Hollywood.
       DV items published between 10 Sep 1969 and 2 Oct 1969 listed the following as cast members: Jack Davidson ; Diane Turley; Jim MacGeorge; Jim Payne; Willie Harris; Tom Moses; Dennis Robertson; Scott Perry; Almira Sessions; Jerry Jones; Freeman King; Mae Clarke; Carol Swenson; Marjorie Dayne; Terry Haskin; and Maggie Malooly.
       A news item in the 18 Mar 1970 LAT reported that Cambridge disapproved of the latest title change to Watermelon Man, and had refused to promote the film. The actor claimed that Watermelon Man had formerly been the title when he had first read the script, and he had only agreed to do the picture if the title, which he considered to be racist, was changed. Cambridge also expressed dismay at a scene he had been coaxed into filming, in which his insurance salesman character is shown shoveling garbage. According to Cambridge, who claimed Van Peebles was influenced only by the opinions of his rich and successful Black friends, the director had refused to show the picture to any civil rights organizations, and supported a sneak preview in New York’s City’s East Side, not known as a Black area. The 28 May 1970 Los Angeles Sentinel predicted that scenes between Cambridge and Estelle Parsons would provoke white bigots, and “the nude bed scene with Cambridge and Kay Kimberly… will throw scores of whites completely out of shape.” A 30 Apr 1970 Los Angeles Sentinel brief had previously noted that a recent screening in New York City had caused “some bad feelings and open ire.” Following that, a preview screening set to take place on 6 May 1970 at the University of California, Los Angeles (UCLA) was cancelled due to “the temper of the times and the content of the pic,” as stated in the 22 May 1970 DV. Arrangements were made for the film to be screened at Bennett’s alma mater, Northwestern University, instead.
       Watermelon Man opened on 27 May 1970 at the Murray Hill and Penthouse theaters in New York City. Critical reception was largely negative. The 28 May 1970 NYT called the picture “dreadfully unfunny,” while the 26 Jun 1970 LAT review described the script as “uninspired” and the direction as “inept,” and also pointed out that Cambridge’s white disguise was unconvincing. The film reportedly was the opening engagement of the new Loew’s Holly 450-seat movie theater on Hollywood Boulevard near Wilcox Avenue.
       The picture grossed $1,568,315 in 1970, according to a box-office chart in the 12 May 1971 Var.
       Ace Publishing planned to release a novelization in summer 1970, as noted in a 6 May 1970 Var brief.