The sentence that helps readers determine the story setting is:
"The morning mist completely gone. The sun was strong and bright, bright, intensifying the color of a row of potted marigolds on the front porch of one of the houses."
This sentence provides specific details about the time of day (morning) and the weather (sunny, mist gone), along with a description of the environment (potted marigolds on a porch), which helps establish the setting of the story.