The review of the climate of the summer of 1983 and associated economic impacts were collated by the state climatologists of 12 states of the Upper Midwest. Their data archives and facilities permitted relatively fast analysis of cooperative station data.
Whereas June temperature was near normal across the region, July and August temperatures were generally higher than the 1951-80 normal, with anomalies of +2°C common, and some August anomalies representing a departure greater than 4σ. Cooling degree days were 50% greater than normal over about 1/3 of the 12- state area.
Precipitation was mixed over the area in June, with the greatest anomalies (ca. 200% of normal) in Illinois, Iowa, Minnesota, and Nebraska. July and August precipitation anomalies were similar to each other, and generally negative. Twenty-five percent of normal precipitation was not uncommon. Indeed, two stations in Nebraska and Missouri recorded no precipitation in August.
The impact of high temperatures and low rainfall resulted in substantially less corn and bean yields than expected, but yields of wheat in Kansas, and corn in Wisconsin were greater than last summer. Electrical demand was generally higher than one year earlier, with increases of +15% to +25% common, and 60% greater this July than July 1982 in South Dakota.
New climatological records of high temperatures, low rainfall, and number of days with high temperatures were established and re-established during the summer, primarily in the southwestern Upper Midwest.
1 State Climate Centers of Illinois, Kansas, Wisconsin, Ohio, North Dakota, Nebraska, Missouri, Minnesota, South Dakota, Indiana, Michigan, and Iowa, respectively.