Snow cover is minimal and grasses and shrubs are lush. The Cornbelt is at the peak of green. In September, some agricultural crops of the Cornbelt are harvested, leaving large areas with lower indications of vegetation. October brings seasonal change. Corn and soybeans have matured and ceased growing.
Fall colors begin as deciduous trees lose their leaves.
Snow cover and cloudiness signal the first signs of winter in November. In December, perennial vegetation is dormant and snow blankets North Dakota and other parts of the conterminous United States. The images have been received, processed, and distributed by the U.S. Geological Survey since 1987. The equation for the vegetation index makes it relatively easy to determine green vegetation and non-vegetated features such as water, barren land, ice, snow, and clouds. With this ability, changes in surface processes over short periods, such as growing seasons, can be monitored.