Heat waves in 20th century

During a period of 160 such days from 31 October 1923 to 7 April 1924, the Australian town of Marble Bar set a world record for the most consecutive days above 100 °F (37.8 °C).

The 1936 North American heat wave during the Dust Bowl, followed one of the coldest winters on record—the 1936 North American cold wave. Massive heat waves across North America were persistent in the 1930s, many mid-Atlantic/Ohio valley states recorded their highest temperatures during July 1934. The longest continuous string of 100 °F (38 °C) or higher temperatures was reached for 101 days in Yuma, Arizona during 1937 and the highest temperatures ever reached in Canada were recorded in two locations in Saskatchewan in July 1937.

The heat waves of 1972 in New York and Northeastern United States were significant. Almost 900 people perished; the heat conditions lasted almost 16 days.

The 1976 United Kingdom heat wave was one of the hottest in living memory and was marked by constant blues skies from May until September when dramatic thunderstorms signalled the heat wave's end.

An estimated 10,000 people perished in the 1980 United States heat wave and drought, which impacted the central and eastern United States. Temperatures were highest in the southern plains. From June through September, temperatures remained above 90 °F (32 °C) all but two days in Kansas City, Missouri. The Dallas/Fort Worth area experienced 42 consecutive days with high temperatures above 100 °F (38 °C), with temperatures reaching 117 °F (47 °C) at Wichita Falls, Texas on June 28. Economic losses were $20 billion (1980 dollars).

During another heat wave in the Summer of 1983 temperatures over 100 °F (38 °C) were common across Iowa, Missouri, Illinois, Michigan, Wisconsin, Indiana, Ohio, Minnesota, Nebraska and certain parts of Kentucky; to this day the summer of 1983 remains on record as one of the hottest summers ever recorded in many of the states affected. The hundred-degree readings were accompanied by very dry conditions associated with drought affecting the Corn Belt States and Upper Midwest. The heat also affected the Southeastern U.S. and the Mid-Atlantic states as well that same summer. New York Times represented articles about the heat waves of 1983 affecting the central United States.

During 1988 intense heat spells in combination with the drought of 1988 caused deadly results across the United States. Some 5,000 to 10,000 people perished because of constant heat across the United States although-according to many estimates-total death reports run as high as next to 17,000 deaths.

The 1995 Chicago heat wave produced record high dew point levels and heat indices in the Chicago area and Wisconsin. The lack of emergency cooling facilities and inadequate response from civic authorities to the senior population, particularly in lower income neighborhoods in Chicago and other Midwest cities, lead to many deaths.

The summer of 1999 saw a devastating heat wave and drought in the eastern United States. Rainfall shortages resulted in worst drought on record for Maryland, Delaware, New Jersey, and Rhode Island. The state of West Viriginia was declared a disaster area. 3,810,000 acres (15,400 km2) were consumed by fire as of mid-Aug. Record heat throughout the country resulted in 502 deaths nationwide.