Saint-Jacob, Illinois is a small village located in Madison County. The climate in this region is classified as humid continental, characterized by hot summers and cold winters. Average temperatures range from 40°F (4°C) in winter to 85°F (29°C) in summer. Precipitation is evenly distributed throughout the year, with an average annual rainfall of 40 inches (1016 mm).

In terms of hydrology constituents, Saint-Jacob is situated near the Wood River, which is a tributary of the Mississippi River. The river provides opportunities for fishing and boating enthusiasts, with various species of fish including catfish, bass, and crappie. The Wood River is also surrounded by scenic landscapes, making it a popular spot for picnicking and hiking.

Outdoor recreation opportunities in and around Saint-Jacob include nearby parks like Tri-Township Park, offering facilities for camping, playgrounds, and sports fields. It also features walking trails, a fishing lake, and a disc golf course. The village itself has a small park, providing a space for relaxation and community gatherings. Overall, Saint-Jacob offers a pleasant climate, proximity to water bodies, and recreational activities for nature lovers and outdoor enthusiasts.