When the pastor and the kids arrive at the trailer park it is raining quite heavily. However, when they are taken to their sleeping quarters, and indeed the rest of the movie, the dirt is dry and dust is continually kicked up.
It is barely noticeable, but when "Norma" brings in a propane tank for grills the valve handle is the old style round. When she turns the handle it changes to the new federally mandated O.P.D. (Overfill Prevention Device) indicator style handle. Then right before she lights her cigarette it switches back to the old style tank handle.
The goof item below may give away important plot points.
At the start of the movie when her boyfriend, Aaron, gets impaled on the fence it protrudes quite far through his chest. Later when the kids are entering the trailer park you see the fence again but there is a crossbar in the fence that would have stopped the spikes penetrating Aaron as far as they did.