Can Rains Still Rescue the US Corn Crop? Gro Finds Clues in Past Droughts

US corn prospects are suffering as dry conditions spread across the Corn Belt in the season’s early weeks. A historical analysis of past crop years that also got off to a rocky start helps to reveal what needs to happen this summer to boost corn’s weakening prospects for 2023. 

The Gro Drought Index, weighted for corn-planted area using Gro’s Climate Risk Navigator for Agriculture, is currently at its highest level for this time of year in two decades. Rainfall has been below normal levels in many key growing states, as seen in this Gro display, and forecasts call for paltry precipitation through the end of June, just ahead of the crop pollination period. 

As a result, Gro’s US Corn Yield Forecast Model is predicting yields significantly below the USDA estimate from its June WASDE report for a record 181.5 bushels per acre. Even if substantial rains were to materialize in July and August, Gro predicts that yields will be hard pressed to reach the current USDA projections. 

Illinois, the No. 1 corn-producing state, is currently experiencing the worst soil moisture readings since at least 2010, as shown in this Climate Risk Navigator display. Meanwhile, conditions in Ohio remain poor as yields decline in the eastern Corn Belt, as can be seen with Gro’s Yield Model Anomaly model, which compares current yield projections against five-year averages.  

2012 and 2006 are the two previous years whose Gro Drought Index readings for this time of year align most closely with 2023, according to Gro’s Analogous Periods model, which identifies past years with similar growing conditions — including drought, temperature, rainfall, and vegetative health — to today. 

In 2012, drought conditions continued to worsen through the summer, reaching “severe” drought levels on the Gro Drought Index by late July. When rains finally came in early September, it was too late for the corn crop, and final yields for the year plunged to 20% below the five-year average while production was down 14.5% from the average. 

Current drought conditions for 2023, as in 2012, are widespread, affecting states in both the western and eastern Corn Belt, as shown in this Gro display. Recovering from the current dry conditions will require plentiful rain — and soon — across a broad swath of the US Midwest. 

2006 also began with worrisome drought conditions, which peaked in early August at the “moderate” drought level on the Gro Drought Index. Still, the US corn crop bounced back, in part because dry conditions were concentrated in western states, and August rains, including in Nebraska, helped alleviate the drought. As a result, corn yields in 2006 were up 3.9%, and production was up 2.3%, from the five-year average. 

Below average precipitation has fallen across much of the US Corn Belt this season. Red areas on this Gro display indicate where rainfall is below the 10-year mean; above average rainfall is shown in blue.