Osage County he thought it would be cool to match the title and do so in August. Then the reality of an Oklahoman summer hit home.
"When we were first scouting for the film we were out there in 118°Fahrenheit. So we waited and shot in September and October when it was only, like, 97°," says the director, laughing.
August: Osage County is adapted from Tracy Letts's Pulitzer and Tony-winning play. Starring Meryl Streep, Julia Roberts, and Ewan McGregor, it is the story of the Weston family, who are thrown together again after a family drama. Since drama is already meat and drink to this clan, it does not take long before the fireworks start.
Streep and Roberts, playing pill-popping matriarch and exasperated daughter respectively, were the pillars around which the cast was built. After they signed up it was a case of waiting until everyone could be in the same place at the same time for nine weeks.
The obvious difference between the play and the movie was that the landscape, often referred to in the play, could be shown. As on the stage, the big skies of Oklahoma stand in contrast to the close-quartered lives of the family.
"It is a strange dichotomy, you can feel very claustrophobic when you are stuck in huge, isolated spaces. There is a lot of Scotland that is like that," says the director of The Company Men.
Wells spent part of his teenage years living in the Midlands and the family used to go camping in Scotland. "I got cold and wet all over Scotland and loved it."
Since its premiere at the Toronto Film Festival last September, the picture has become famous for a dinner party scene where more than just barbs fly.
Wells had stunt doubles ready to take over from Streep and Roberts, but the actors decided to go without, sorting the action out between themselves.
Wells recalls: "Julia said, 'Well, how should I go at this?' and Meryl said, 'Just attack me!' So she came across the table and slammed (Meryl) down on the floor. At the end of the scene I was like, 'And cut! And is everybody okay over there?'"
The house was bought for the production. "One of the things we did during the rehearsal process was have the actors stay in their childhood rooms. The adults went into their spaces, and lived in those spaces. People ate in the dining room. It gave everyone a sense of what the surroundings were, and I think it made a huge difference in the way that people interacted with their surroundings in the film."
Wells knew McGregor from ER, the show on which he was executive producer for 15 years, taking the medical drama from creation to headlines-generating finale. Another connection from those ER days was George Clooney, once a star of the show and now producer of August: Osage County. Roles had changed, says Wells, but little else.
"It was a little bit of a transition for him and for me because I had been his boss for years on ER and he was my boss on this. But it was just an inverse of the same conversation we were always having, which is how authentic is this performance at this moment, is it becoming too theatrical, too melodramatic?
"A lot of the conversation always on ER was the worry that we had, because the situations by their nature are melodramatic, you have a child who is ill or whatever it is, that we wanted to make certain it was always authentic, and that we were underplaying it and not just playing it for the obvious pathos."
ER was a ratings phenomenon. While it had many things in its favour, including its stemming from an idea by Michael Crichton, the casting was critical, says Wells.
"A tremendous amount of the responsibility for an executive producer, producer, director, is making certain you have the right cast. If you spend enough time getting the right cast your probability of success is much higher. Style is a necessary part of what you are doing, all of those things, but none of it works unless you have the right actor in the right role."
Wells was also the executive producer on The West Wing and is at the helm in the American version of the Channel 4 drama Shameless. On the West Wing he helped to pioneer the "walk and talk" style now commonplace in TV drama. Being such a dialogue and politics driven show, I wonder if it was tough to get the green light initially. It was not the first time he had to fight to convince station controllers that an idea would work.
"I wish I could say that anything I had done was really easy to get made," he says. ER took three years, and The West Wing waited around for two and a half years. It is the price to be paid for doing something that little bit different, says Wells. "The things that are worth doing tend to require more effort because they are not exactly what is already there, so someone is taking a risk on the unknown."
He had the same wait with The Company Men, his 2010 drama about the financial crash. Starring Ben Affleck, Chris Cooper (who also stars in August: Osage County) and Tommy Lee Jones, it was first written during the 2001 recession.
Though he has a long pedigree in the theatre and television - shows produced by him have attracted 55 Emmys in total - August: Osage County is only Wells's second feature film. He is not, though, lost to TV now.
"When I started coming out of the theatre and into film and television you really had to pick. Over the last seven or eight years writers, directors, everybody, is moving back and forth, which is a great thing."
August: Osage County opens on January 24