Unusually hot weather spread from the West across much of the Corn Belt and into the Eastern United States last week, sapping soil moisture from areas already stressed by the lack of significant rainfall, according to the latest Weekly Weather and Crop Update from the World Agricultural Outlook Board (WAOB). The hot, dry conditions cause growing concern as the corn crop approaches the critical and sensitive pollination stage.

Summer heat dries nation’s midsection

Weekly temperatures averaged at least five degrees Fahrenheit above normal in much of the Corn Belt for the week ending June 23, and most of the nation experienced higher-than-normal temperatures, with the exception of the Southeast, northern border states and Pacific Northwest. In Colorado, temperatures averaging more than 10 degrees above normal helped fuel an ongoing outbreak of wildfires.

The most current Drought Monitor map shows moderate to extreme drought across the Southwest, Southern and Central Plains, with areas of drought extending into the Corn Belt.

The dry conditions are beginning to take a toll, which shows up in week-to-week changes in estimated crop conditions. The report indicates that for the week ending June 23, 56 percent of the corn crop was in good to excellent condition, down 7 percentage points from 63 percent the previous week and 12 percentage points below the same time last year. Soybean condition also has declined, with 53 percent of the crop in good to excellent condition, down 3 percentage points from the previous week and 12 percentage points below the same time last year.

The heat also has taken its toll on pasture and range conditions, with USDA rating 34 percent of the nation’s pasture and range as good to excellent condition, compared with 40 percent the previous week and 53 percent a year ago. The report rates 34 percent of U.S. pasture and range as poor or very poor, compared with 28 percent the previous week and 26 percent a year ago.

Internationally, the report shows a range of conditions in key agricultural areas.

  • Europe: Widespread rainfall maintained abundant soil moisture for winter and summer crops across much of the continent, although heat and dryness stressed crops in the Balkans.
  • Western former Soviet Union: Favorably wet weather in western and northern areas contrasted with periods of stressful heat for filling wheat in the south.
  • Eastern former Soviet Union: Showers boosted soil moisture for jointing spring wheat in Russia, but the rain bypassed parts of northern Kazakhstan.
  • Middle East: Scattered showers in Turkey provided supplemental moisture for irrigated summer crops but did not cause significant winter grain harvesting delays.
  • South Asia: Monsoon rains continued to promote rice, groundnut, and cotton planting in central and eastern India.
  • East Asia: A pair of tropical cyclones dominated the weather pattern for the region, bringing heavy rainfall to southern China and Japan.
  • Southeast Asia: Rainfall continued to be light across much of Thailand, while Tropical Cyclone Talim brought more flooding to the northwestern Philippines.
  • Australia: Rain favored winter grain and oilseed development throughout much of the wheat belt.
  • Australia: Rain continued to benefit wheat, barley, and canola in western and southeastern Australia.
  • Brazil: Locally heavy showers persisted throughout the south, maintaining locally excessive moisture for crops and causing some flooding.
  • Mexico: Beneficial rain overspread the southern plateau corn belt.
  • Canadian prairies: Warmer weather was needed for emerging spring grains and oilseeds.
  • Southeastern Canada: Warm, mostly dry weather sped development of winter grains and summer crops.

Read the full WAOB report online.