What causes lemons to go bad overnight?

Lemons can go bad overnight due to a combination of factors such as high humidity, exposure to ethylene gas from other fruits, and improper storage conditions. When lemons are stored in a warm, moist environment, they can develop mold or rot more quickly. Additionally, if they are bruised or damaged, they become more susceptible to spoilage. To prolong their freshness, it's best to store lemons in a cool, dry place or in the refrigerator.