Prairie Coteau Watershed Improvement & Protection Project


The climate of the project area is classified as Sub-humid Continental. 


Mean climatic conditions of the area are:

  • Winter Average Daily Minimum Temperature - 4 degrees F
  • Summer Average Daily Maximum Temperature - 82 degrees F
  • Total Annual Precipitation - 21 inches

Average Seasonal Snowfall - 31 inches


Approximately 75 percent (=16 inches) of the annual precipitation falls between the months of April to September. Tornadoes and severe thunderstorms occasionally strike. These storms, usually local and of short duration, occasionally produce heavy rainfall. (Data from Webster, SD reporting station)


The area has seen one historic period of drought in the 1930s and a period of above normal precipitation that led to widespread flooding in the late 1990s. 


It was reported that the only lakes with enough water to support fisheries in the region during 1933 were Blue Dog, Enemy Swim, Pickerel, and Roy Lakes. Beginning in the mid-1990s, and lasting for the next several years, a period of abnormally wet and cool weather occurred causing several northeastern South Dakota Lakes and wetlands to rise well above recorded historical levels (See Late Holocene Flooding listed below). 


The depths of both Bitter and Waubay Lakes located in Day County increased by 20+ feet during this period flooding croplands, roads, and farmsteads. Dozens of large wetlands are now deep enough to support fisheries and public accesses have been developed on many of these waterbodies.


Click on titles to display lake level fact sheets and climatic reports listed below:


2021 Bitter Lake Levels 


Bitter & Waubay 2021 Lake Levels Graph


2021 Blue Dog Lake Graph


2021 Blue Dog Lake Levels


2021 Enemy Swim Lake Levels


2021 Pickerel Lake Levels


 2021 Waubay Lake Levels 


1998-2018 WNWR Precipitation Graph


Late Holocene Flooding & Drought in the Northern Great Plains


Weather Observations, Fort Sisseton, SD (1866-1889)