The growing season ranges from 111 to 136 days and is longer in the south. This subsection is drained by the Red River of the north, which forms the west boundary. The Red River flows north into Canada. The drainage network in this unit is minimally developed. Rivers and streams meander extensively through this level topography.
Flooding is common in early spring and can cause major problems due to level topography.
Frozen conditions to the north can cause water to back up and flood large areas. There are few lakes present. They are most common in the southeast on a till plain. Characteristically, they are shallow and perched. The upland prairie was dominated by bluestems, Indian grass, and several other grasses.