The poem "Water Margin," also known as "Outlaws of the Marsh," is set primarily during the late spring and summer seasons. This conclusion is drawn from the narrative and thematic elements present in the text. The story revolves around a group of outlaws who take refuge in the mountains during a period of political instability and social unrest. The lush, verdant landscapes and frequent references to the heat of the sun and the growth of crops strongly suggest a setting in the warmer months. Additionally, the outlaws' reliance on agriculture and the abundance of fish in the rivers further indicate a season when nature is at its peak. Historical context also supports this, as the story is believed to be based on real events that occurred during the Song Dynasty, which experienced its peak in the 12th century, a time when spring and summer were characterized by favorable weather conditions for farming and outdoor activities.