Despite being set in summer, as its title suggests, some of the scenes were shot in winter. This is particularly clear during Katharine Hepburn's visit to San Marco's Square: while watching the clock tower, she sees a parade of wooden statues coming up of the clock and marching around it; those statues are actually the Three Wise Men, and they appear only once every year, on January 6th.
Having been cast as the older widowed concierge of the hotel, David Lean was upset to find that Isa Miranda had recently had a facelift and looked too young for the part. Since recasting at that late stage was out of the question, Lean went with it. Aside from her appearance, Lean was also displeased with her performance. She was having trouble working up tears for her scene with Darren McGavin, which was frustrating Lean to no end. Katharine Hepburn said she would coach Miranda, took her aside and slapped her sharply across the face. Miranda was shocked and then began to tear up. Lean was impressed and told Hepburn she was a tougher director than he.
Katharine Hepburn's apartment is actually an amalgam of three different locations. The door through which she enters the apartment belongs to the Trattoria Sempione, a restaurant that still exists today. Her bedroom belongs to an apartment two miles away in the suburb of Dursoduro, and the terrace was a purpose-built set in Compo San Vio.
Katharine Hepburn was more than impressed with her experience working with David Lean. She even asked to sit in on the editing sessions with him to watch him at work. In her autobiography, she wrote, "[Summertime] was told with great simplicity in the streets, in the Piazza San Marco. We would shoot in tiny streets only a few feet wide. The sun would come and go in a matter of minutes. It was a very emotional part, and I tell you I had to be on my toes to give David enough of what he wanted practically on call. But it was thrilling... He seemed to me to simply absorb Venice. It was his. He had a real photographic gift. He thought in a descriptive way. His shots tell the story. He was capable of a sort of super concentration. It made a very deep and definite impression on me, and he was one of the most interesting directors I ever worked with. Wasn't I lucky to work with him?"
Once the script was in hand, the cast and crew made its way to Venice to begin prepping the locations. David Lean had accepted the job of directing it in part because of a desire to no longer do soundstage work but work on locations outside. He remarked that working on a soundstage made it feel as though one was working in a "pitch-black mine... I prefer the sun." He set out about Venice, picking out locations and taking pictures. Lean would fall in love with Venice and later live there part of every year. Once location scouting was completed, Lean and his cast and crew were ready to begin work.
"Summertime" was an adaptation of the Broadway play "The Time of the Cuckoo" by Arthur Laurents. The stage production starred Shirley Booth and opened on Oct. 15, 1952 at the Empire Theatre in New York and ran for 263 performances.
Shooting schedules for Katharine Hepburn often ran from morning to night, giving her, on average, twelve hours of shooting per day. The hot sun of Venice caused Hepburn to remark on more than one occasion that it was hotter than her shoots in Africa for The African Queen (1951).
David Lean encountered problems with the locals and had to donate money for the restoration of a local church to break the deadlock. It was the height of tourist season and several merchants and gondoliers claimed that filming was disrupting their business. Lean paid for lost income as well as work on the church.
Upon seeing the completed film, Production Code Administration head Geoffrey Shurlock notified United Artists executives the film would not be approved because of its depiction of adultery. Of particular concern was the scene in which Jane and Renato consummate their relationship. Eighteen feet of footage was deleted, and the PCA granted its approval. The National Catholic Legion of Decency, however, objected to a line of dialogue that finally was trimmed, and the organization bestowed the film with a B rating, designating the film "morally objectionable in part.
According to the film's pressbook, ninety percent of the picture was shot in exterior locations in Venice, including the island of Burano. The remaining ten percent, all interiors, were shot at the Scalera Studios in the commercial district of Venice.
The story was also later adapted as a Broadway musical called "Do I Hear A Waltz" by Arthur Laurents with songs by Richard Rodgers and Stephen Sondheim. The show opened at the 46th Street Theatre on March 18th, 1965 and ran for 220 performances. Laurents later revised the script and a new production was staged in 2000 at the Pasadena Playhouse in New Jersey. Recordings of both productions are available for purchase on specialist websites.
One of the most contentious items in the picture for censors was a line spoken by Renato when he chastises Jane for her simplistic attitude toward sexual relationships. In the released film, Renato tells her that she is like a hungry child and should eat the ravioli in front of her. According to a August 24, 1955 Daily Variety article, the National Catholic Legion of Decency strongly objected to the sequence as it was originally shot, in which Renato said: "You are like a hungry child who is given ravioli to eat. 'No' you say, 'I want beefsteak!' My dear girl, you are hungry. Eat the ravioli." Although the PCA had not objected to the line, the legion threatened to issue a condemned rating for the film unless the line about "beefsteak" was deleted from the picture. The line was eliminated and Summertime eventually received a "B" rating from the Legion of Decency. One modern source suggests that it was Ilya Lopert's partner, Robert Dowling, who ordered that the "beefsteak" line be deleted.
The filming was one without any behind-the-scenes acrimony. Katharine Hepburn expressed how, early on, everything seemed right, "Constance Collier, my friend, and Phyllis Wilbourn, her secretary, were going to go with me. Spencer was going to do The Mountain (1956) in the French Alps, so everything was perfect. He was busy - I was busy." After a brief mix-up, in which Hepburn put her two friends up in a house far from Venice, she got them an apartment on the Grand Canal and never had to suffer for loneliness while filming. That didn't mean she didn't have to suffer other things.
Hal B. Wallis and agent Irving "Swifty" Lazar were among those interested in purchasing the play for production on the screen. Wallis wanted to purchase the play, but Shirley Booth refused to work with him because he had told her that she was "too old" for the film version.