Heat wave of 1931

The Event Period of abnormally high air and soil temperatures that afflicted much of the continental United States

Dates Late spring through early autumn, 1931, peaking from June 18 to July 2, 1931

Place Continental United States

The heat wave set unprecedented air and soil temperature records and worsened conditions for wind erosion of topsoil by killing both ground plant cover and the supporting root systems. This initiated a massive loss of marginal soils, the slow collapse of much of the U.S. farming industry in the Great Plains and the Midwest, and the massive dust storms that began in 1932 and created the “Dust Bowl.”

The impact of long-term drought on the continental United States during the 1930’s was foreshadowed in 1931. The winter of 1930-1931 had insufficient rainfall, and the Mississippi and other rivers were at record low levels in January, 1931. Rainfall levels for February were below normal for more 50 percent of the country, while temperatures continued to be above expected ranges. While the spring of 1931 had relatively more moisture, a marked shift in temperature across most of the interior United States began on June 17.

An area of increasing heat, augmented by dry westerly winds, set in over the southern Great Plains and the interior valleys, gradually widening its scope until virtually all of the United States between the Rocky Mountains and the Appalachians was engulfed by it. Temperatures of more than 100 degrees Fahrenheit were recorded in every state, with the central and northern plains reporting extreme readings ranging between 107 and 115 degrees, the latter in South Dakota. The high temperatures continued for much of July, with lower-than-normal humidity levels. Many areas reported readings of more than 110 degrees. The rain returned in August, but excessively high heat continued until nearly the end of the month, with all areas in the East except New England experiencing unusually high temperatures, up to 105 degrees. The West peaked at 123 degrees in California. September, 1931, was the warmest September on record, with a temperature range between four and ten degrees above normal.

The intense heat presented different problems for major urban areas; their populations experienced cases of heat prostration, canned liquids reached explosive temperatures, and water supplies were challenged. On June, 29, Chicago reported forty-four deaths; by July 2, 1931, the total number of deaths from heat-related causes across the United States stood at 1,016. In many cities, lawns in public parks were opened to provide spaces for relief, and record crowds flooded coastal beaches, with an estimated one-half million people at Coney Island in one day. On July 1, a low-pressure area moving eastward across the Great Plains brought rain to Iowa, Minnesota, and the Dakotas, dropping temperatures between twenty and forty degrees. By late October, colder air had moved into the Great Plains and Midwest, breaking the grip of the extreme heat and bringing vitally needed rains across most of the damaged interior of the country.

Impact

Already damaged by a drought that had begun in 1930, the American agricultural industry was hit hard by the heat wave of 1931. Primary water sources shrank noticeably, depriving farmers of the water necessary to stave off the effects of the heat on both crops and livestock. Unrelieved high soil temperatures also killed grasses and other essential components of the ground cover vital to maintaining stable soils in marginal environments, resulting in a rise in wind erosion across much of the southern Great Plains. The failure of small farmers’ fields directly impacted the economies of twenty-two states, forcing many communities into or close to bankruptcy and pushing many families off land that literally was crumbling beneath them. Shrinking water supplies also had an effect on the national health. Many people were forced to take untreated water directly from springs, wells, and rivers, thus increasing the risk of typhoid. In some of the affected states, the losses of regular sources of standard foods such as milk and meat caused a high number of malnutrition-related illnesses. By late June, 1931, some farmers in the Corn Belt were sleeping in the daylight and tending their fields by moonlight, and in many towns regular church services were held to pray for rain. Crops most heavily impacted were tobacco, corn, oats, and fruit grown in orchards. The dust storms of 1932 and succeeding years forced substantial changes in farming and soil conservation strategies across much of the American grain belt.

Bibliography

Egan, Timothy. The Worst Hard Time: The Untold Story of Those Who Survived the Great American Dust Bowl. Boston: Houghton Mifflin, 2006.

Hunter, Herbert C. “The Weather of 1931 in the United States.” Monthly Weather Review (December, 1931): 483-484.

Worster, Donald. Dust Bowl: The Southern Plains in the 1930’s. New York: Oxford University Press, 1979.