KANSAS CITY, MISSOURI, US — Improved farm management practices and better seed and plant genetics have provided the impression that grain and oilseed production is infallible. Recent production years in the United States and other areas in the world have surprised many producers and analysts how resilient crops are while under stress. However, it has become obvious that the biggest killer of crops is temperatures and not precipitation or lack thereof. 

US production in recent years has outperformed expectations with yields that have managed to remain very high with only a small portion of “normal” rainfall. Last year’s five months of well-below-normal precipitation in key summer grain and oilseed production areas would have wiped out production in the 1980s. Recent years of dryness have still managed to produce some amazing yields, and total production continues to grow rather than shrink in the face of dryness. World Weather, Inc. believes the true test of genetics and farm management may come in the summer of 2024 due to the potential for a hot summer. 

One of the largest features missing from recent production years in the United States has been truly oppressive heat with no relief for long enough periods of time to damage crop production potential. The coming summer offers an opportunity for that to change, and modern agricultural technology and ingenuity may be put to the test in the Great Plains and western Midwest. 

World Weather, Inc. speaks of cycles in the atmosphere that are always in play. Many different weather patterns are at work influencing the atmosphere each year, and the period for each pattern to repeat is different. That is why weather is different each year even when it looks like a single pattern is repeating. It is like pulling the arm of a slot machine or playing the roulette wheel when it comes to determining the weather for each year. This year’s spin of the wheel is suggesting greater potential for hot weather to impact the central United States than in recent years. 

February temperatures were at or near record-warm levels for much of the Midwest, allowing greater evaporation and drying during the middle of winter, which is never a great feature to have when the growing season is approaching. 

The lunar cycle already is promoting a ridge of high pressure in the middle of North America during the summer of 2024. Ridges of high pressure, when strong enough, can block precipitation and induce warmer-than-usual weather. A summertime ridge may begin to evolve in May of this year and already be suppressing rainfall in many areas by early July. Each time this cycle has played out in the past it has been slightly drier than usual in the spring across the Plains, Midwest and Delta, and more notably dry during the summer months.

Most forecasters this year were expecting El Niño to be a greater precipitation producer in the United States than what has occurred thus far. Some of the moisture deficits that were present last summer are still prevalent deep into the soil in Iowa and other parts of the Midwest and central Plains. Even though a part of the Delta had been inundated with rain in late January and early February, it still has some moisture deficits remaining from last summer’s drought. In recent weeks, there has been a mysteriously dry and warm bias in the heart of North America. 

February temperatures were at or near record-warm levels for much of the Midwest, allowing greater evaporation and drying during the middle of winter, which is never a great feature to have when the growing season is approaching. 

Many years ago, World Weather, Inc. assessed the 10 warmest Februarys and found that they often were followed by warmer-than-usual Julys. While that is not enough to rely on for a summer forecast, the lunar cycle has promoted a frequent occurrence of very warm to hot summers. The years looked at included 2006, 1988, 1970, 1952, 1934 and 1916. Many of these summers were warmer biased, but one feature that stands out in the Plains and western Midwest corn and soybean production area is a greater number of 100-degree days relative to normal. 

Many of these years produced more excessive heat than other years, with 1934 leading the way. However, 2006 was also a notable summer with excessive heat in the Plains and western Corn Belt, and 1970 was also in that category. The least amount of excessive heat among those years was in 1916, but each of the other years reported numerous days of 100-plus degree heat from Texas and a part of the western Delta to Illinois, Missouri, Iowa and South Dakota. The Plains were hottest.

The heat showing up in the lunar cycle years along with unusually warm February weather that could lead to an unusually warm to hot July (by correlation of past years) makes the heat potential a little more real. But that is not all.

Will La Niña arrive this summer?

The US National Ocean and Atmospheric Administration (NOAA) has a forecast model that has been consistently predicting La Niña could emerge by June of this year. In the past, years that begin with a moderately strong El Niño and transition to La Niña by mid-year have tended to be drier and warmer than usual. That agrees with the lunar cycle and our correlation with unusually warm Februarys. 

Temperatures were excessively hot in the Northern Hemisphere last summer and similar conditions occurred in Australia in recent weeks and in Argentina earlier this summer as well as Brazil during the spring.

World Weather, Inc. also has been monitoring world weather patterns for decades and notes the changes associated with the January 2022 Hunga Tonga volcanic eruption (which was the greatest in modern history). Global temperatures have spiked even higher than climate trend models predicted, and it may be due to the increase in stratospheric moisture resulting from the volcanic eruption. 

Temperatures were excessively hot in the Northern Hemisphere last summer and similar conditions occurred in Australia in recent weeks and in Argentina earlier this summer as well as Brazil during the spring. The effects of the volcanic eruption should slowly dissipate over the next couple of years, but there may be enough heat remaining in the atmosphere to bring excessive temperatures to the central United States this summer since there is already support for warmer-than-usual conditions.

If all these cycles and atmospheric influences come together and support one another, the US Plains and western Corn and Soybean Belt may be subjected to one of the hottest summers in recent years. That could impact summer grain and oilseed production in 2024 in a more notable manner relative to the recent past drier summers that had no excessive heat. 

Drew Lerner is senior agricultural meteorologist with World Weather, Inc. He may be reached at [email protected]. World Weather, Inc. forecasts and comments pertaining to present, past and future weather conditions included in this report constitute the corporation’s judgment as of the date of this report and are subject to change without notice.