We constantly hear all of the talk about weather extremes and climate change, but it was on this day back in 1935 that “The Dust Bowl” heatwave reached its peak, with temperatures of 109°F in Chicago, Illinois and 104°F in Milwaukee, Wisconsin. The drought itself actually came in three waves, 1934, 1936, and 1939–1940, but some regions of the High Plains experienced drought conditions for as many as eight years.
Even back then a lot of the concerns and problems were blamed on new technology and innovation. The demand for more food and rapid mechanization of farm equipment, especially small gasoline tractors and widespread use of the combine harvester contributed to farmers’ decisions to convert arid grassland, much of which received no more than 10 inches of precipitation per year to cultivated cropland. That unanchored soil then turned to dust during the drought, which the prevailing winds blew away in huge clouds that sometimes blackened the sky. These choking billows of dust – named “black blizzards” or “black rollers” – traveled all the way across the country, reaching as far as New York City and Washington, D.C. On the plains, the visibility was often reduced to 3 feet or less.
The drought and erosion of the Dust Bowl directly affected +100,000,000 acres. The Dust Bowl forced tens of thousands of poverty-stricken families, who were unable to pay mortgages or grow crops, to abandon their farms, and take massive losses.
Remember, the federal government encouraged settlement and development of the Plains for agriculture via the Homestead Act of 1862, offering settlers ”quarter section” 160-acre plots. With the end of the Civil War in 1865 and the completion of the First Transcontinental Railroad in 1869, waves of new migrants and immigrants reached the Great Plains, and as anticipated greatly increased the acreage under cultivation.
Interestingly, the weather was very cooperative in the early years of the program. Recognizing the challenges of farming and wanting the nation to be self-sufficient, the United States government expanded on the 160 acres offered under the Homestead Act – granting 640 acres to homesteaders in western Nebraska under the Kinkaid Act (1904) and 320 acres elsewhere in the Great Plains under the Enlarged Homestead Act of 1909. As you can imagine, waves of European settlers arrived in the plains at the beginning of the 20th century.
The combined effects of the disruption of the Russian Revolution, which decreased the supply of wheat and other commodity crops, and World War I increased agricultural prices; this demand encouraged farmers to dramatically increase cultivation.
After fairly favorable climatic conditions in the 1920s with good rainfall and relatively moderate winters, which permitted increased settlement and cultivation in the Great Plains, the region entered an unusually dry era in the summer of 1930. During the next decade, for whatever reason, the weather dramatically shifted and delivered many parts of the plains some of their driest calendar years on record. In fact, some areas went more than 10 years without a sign or hint of normal rainfall.
After much data analysis, the causal mechanism for the droughts have been linked to ocean temperature anomalies. Specifically, Atlantic Ocean sea surface temperatures appear to have had an indirect effect on the general atmospheric circulation, while Pacific sea surface temperatures seem to have had the most direct influence on the drought in the Plains. Who really knows???