Marengo is a small town located in Iowa County, Iowa. The climate in Marengo is classified as humid continental, characterized by hot summers and cold winters. Average high temperatures range from the mid-80s Fahrenheit (around 30°C) in summer to the mid-30s Fahrenheit (around 2°C) in winter. Precipitation is fairly evenly distributed throughout the year, with an average of around 35 inches (89 cm) annually.

Hydrology constituents in Marengo are primarily influenced by the Iowa River, which flows nearby. The river provides recreational opportunities such as fishing and boating. The water quality is generally good, supporting a variety of aquatic life.

Outdoor recreation opportunities in Marengo and its surrounding areas are abundant. The town is home to several parks, offering facilities for picnicking, hiking, and playing sports. The nearby Amana Colonies, a historic community, provides additional opportunities for outdoor exploration, including hiking and biking trails. The Iowa County Conservation Board manages several parks and preserves in the county, offering activities such as camping, fishing, and wildlife observation.

In conclusion, Marengo, Iowa, offers a pleasant climate with distinct seasons, influenced by the Iowa River. The hydrology constituents are largely shaped by the river, providing opportunities for water-based activities. The area also boasts various outdoor recreation opportunities, including parks, trails, and preserved natural areas.