Symbolism, Imagery, Allegory
Even the weather in "A Good Man Is Hard To Find" is creepy.
The surreal conditions—the sky is cloudless and sunless—is mentioned several times after the family has the car accident, most notably by The Misfit:
"Ain't a cloud in the sky," he remarked, looking up at it. "Don't see no sun but don't see no cloud neither." (80)
This peculiar sky is also mentioned by the narrator after the grandmother's been shot:
Hiram and Bobby Lee returned from the woods and stood over the ditch, looking down at the grandmother who half sat and half lay in a puddle of blood with her legs crossed under her like a child's and her face smiling up at the cloudless sky. (137)
If there's no sun and no clouds, we would expect it to be...night. But it's still daylight—the grandmother even remarks on how fine the weather is.
This sky is also an ambiguous image, in that it has two sides. On the one hand, there's something barren and austere about the cloudless, sunless sky because it's empty. You might see this emptiness as a reflection of the family's extreme situation at the end of the story: they're dying in the middle of nowhere, without anyone to help them.
You might also think this sky complements the character of The Misfit. The Misfit's "empty" inside—he's lost all sense of good, but isn't passionate about evil either. He's also the character who, unlike the grandmother, isn't concerned with appearances, and wants to get straight to the heart of things. It may be significant that he's the first character to mention the sky.
On the other hand, a cloudless sky is often considered an ingredient of a beautiful day. In fact, the beautiful, cloudless day contrasts sharply with the events that are happening under it; murders in the woods in the middle of nowhere should happen during a dark and stormy night, not a beautiful cloudless day. There's something jarring about that which makes it all the more disturbing to the reader.
But when it returns for the last time in the description of the grandmother's smiling face, the image of the cloudless sky seems to transform, suggesting the peace the grandmother found in her last moment.