2023 Corn Yield Forecasts as of Aug. 23

2023 Corn Yield Forecasts as of Aug. 23

This article summarizes the simulated crop stages and yield forecasts performed on Aug. 23 for 40 locations across the U.S. Corn Belt using the UNL Hybrid-Maize crop model; the data can be seen in Table 1. Details on the underpinning methodology to simulate phenology and forecast end-of-season yields, as well as on interpretation and uses of yield forecasts, are described in a previous article.

Over the past three weeks, weather remained near the historical average except for a combination of high rainfall and low solar radiation in MO and parts of IL and IN. Overall, nighttime temperature matched historical records throughout the entire Corn Belt. A summary of weather conditions during the last three weeks is shown in Figure 1.

Weather conditions summary chart
Figure 1. Daily solar radiation, maximum and minimum air temperature (Tmax and Tmin), total rainfall, and total reference grass-based evapotranspiration (ET) for the time period between Aug. 2 and Aug. 22, 2023. Vertical bars indicate the range for these variables based on 20-plus years of weather records. The horizontal thick line indicates the long-term average and the red dots indicate the 2023 values.

Table 1. Data from simulations of 2023 end-of-season corn yield potential and real-time crop stage performed on Aug. 23.
LocationWater regimeLong-term average yield (bu/ac) §Range of Yp forecasts as of Aug 23 (bu/ac)¶ 25thRange of Yp forecasts as of Aug 23 (bu/ac)¶ 75thProbability (%) of 2023 yield to be: Below (relative to the long-term Yp)†Probability (%) of 2023 yield to be: Near (relative to the long-term Yp)†Probability (%) of 2023 yield to be: Above (relative to the long-term Yp)†Simulated current crop stage*
NE Alliance Irrigated 193 190 217 12% 50% 38% R4, Dough
Beatrice Dryland 160 188 200 0% 0% 100% R5, Dent
Irrigated 229 218 229 0% 100% 0% R5, Dent
Clay Center Dryland 155 84 107 95% 5% 0% R4, Dough
Irrigated 245 226 241 15% 85% 0% R4, Dough
Concord Dryland 173 132 158 68% 32% 0% R4, Dough
Irrigated 248 242 264 2% 85% 12% R4, Dough
Elgin Irrigated 252 237 258 9% 80% 11% R4, Dough
Holdrege Dryland 112 107 130 0% 66% 34% R5, Dent
Irrigated 242 231 254 11% 74% 14% R4, Dough
McCook Dryland 86 99 107 0% 0% 100% R5, Dent
Irrigated 224 205 221 10% 90% 0% R5, Dent
Mead Dryland 181 202 214 0% 17% 83% R5, Dent
Irrigated 234 228 242 0% 98% 2% R5, Dent
North Platte Dryland 90 121 137 0% 0% 100% R4, Dough
Irrigated 234 228 264 7% 59% 34% R4, Dough
O'Neill Irrigated 226 230 260 3% 53% 45% R4, Dough
IA Ames Dryland 228 215 228 6% 91% 3% R5, Dent
Crawfordsville Dryland 227 165 178 100% 0% 0% R4, Dough
Lewis Dryland 205 201 210 0% 100% 0% R5, Dent
Nashua Dryland 228 170 188 97% 3% 0% R4, Dough
Sutherland Dryland 208 191 218 12% 85% 3% R4, Dough
IL Bondville Dryland 235 237 252 0% 81% 19% R4, Dough
Freeport Dryland 213 199 228 12% 73% 15% R4, Dough
Olney Dryland 191 212 217 0% 21% 79% R5, Dent
Peoria Dryland 211 238 253 0% 10% 90% R4, Dough
Springfield Dryland 182 223 233 0% 0% 100% R5, Dent
IN Butlerville Dryland 224 221 231 0% 90% 10% R4, Dough
Columbia City Dryland 224 251 270 0% 20% 80% R4, Dough
Davis Dryland 230 247 260 0% 55% 45% R4, Dough
West Lafayette Dryland 236 239 253 0% 85% 15% R4, Dough
KS Garden City Irrigated 217 194 205 27% 73% 0% R5, Dent
Hutchinson Dryland 99 Black layer on Aug. 10. Final yield: 97 bu/ac Matured
Manhattan Dryland 137 Black layer on Aug. 16. Final yield: 160 bu/ac Matured
Scandia Dryland 129 96 97 100% 0% 0% R5, Dent
Irrigated 226 202 210 41% 59% 0% R5, Dent
Silverlake Dryland 141 Black layer on Aug. 18. Final yield: 164 bu/ac Matured
Irrigated 209 210 215 0% 100% 0% R5, Dent
MI Ceresco Dryland 180 182 215 5% 32% 64% R3, Milk
MN Eldred Dryland 114 80 106 59% 41% 0% R4, Dough
Lamberton Dryland 212 187 202 42% 58% 0% R4, Dough
Waseca Dryland 219 199 213 23% 77% 0% R4, Dough
MO Brunswick Dryland 181 94 97 100% 0% 0% R5, Dent
Monroe City Dryland 175 134 138 100% 0% 0% R5, Dent
St. Joseph Dryland 169 205 210 0% 0% 100% R5, Dent
ND Dazey Dryland 108 84 120 39% 36% 25% R4, Dough
OH Custar Dryland 208 219 239 3% 45% 53% R3, Milk
South Charleston Dryland 216 220 248 3% 55% 42% R4, Dough
Wooster Dryland 210 194 229 16% 66% 18% R2, Blister

§Long-term (last 20-plus years) potential yield at each location and surrounding area.
¶ Range of forecasted 2023 potential yields based on average planting date in 2023, indicating the potential yields in the 25th and 75th percentile of the potential yield distribution (associated with respective adverse and favorable weather scenarios during the rest of the season).
† Probability of obtaining a 2023 yield below (<-10%), near (±10%), and above (>10%) than the long-term potential yield at each location.

Simulated Corn Stage Across 40 Locations

Corn has entered the dough stage across a majority of sites, except for three sites in the eastern fringe of the region. At this point, corn has reached kernel dent stage in central to southern regions of the Corn Belt, and has even reached black layer at three sites in KS (Figure 2). Current corn stage is similar to that reported by mid-August last year.

Figure 2. Simulated developmental stage for irrigated and rainfed corn at each location. R2: blister; R3: milk; R4: dough; R5: dent; physiological maturity: Matured. Separate maps are shown for irrigated corn (top) and rainfed corn (bottom).

Irrigated Corn: Near or Below-average Yields are Expected

The forecasted range of irrigated corn yield potential for each location, along with the probabilities for yields above, near or below average, are shown in Figures 3 and 4. Most irrigated sites (eight out of 13) show a high probability (>75%, that is, three out of four chances) of near-average yield potential. Near-average yield is also likely in the rest of the sites. At this point, the forecasted scenario for irrigated maize in the current season appears more favorable than that of 2022.

Rainfed Corn: Yield Potential is Highly Variable Across Rainfed Sites

Forecasted yield potential is highly variable across the 35 rainfed sites (Figures 3 and 4). Consistent with our previous forecast, two distinct regions have a high probability of experiencing below-average yields. The first region includes portions of ND, MO and eastern IA, while the second covers the northeastern and south-central areas of NE, along with north-central KS. Compared with our previous forecast, the environmental conditions during the past three weeks have increased the probability of above-average yield potential in the eastern states (most of IL, IN and OH). Overall, 11 sites distributed across IL, IN, NE, KS and northwestern MO have a high probability (>75%, that is, three out of four chances) of above-average yields (Figures 3 and 4). Additionally, seven sites, primarily situated in western IA and the eastern part of the Corn Belt (IN and IL), exhibit a high probability of achieving near-average yields.

Spanning from west to east and in comparison with the 2022 forecast, the forecasted scenario for rainfed maize appears to be more favorable in the western region (NE, ND, northern MN, and most of IA and KS), more pessimistic in central areas (MO, northeastern IA, south of MN, and western IL), and largely similar in the eastern fringe of the Corn Belt (IL, IN, MI and OH).

Figure 3. Vertical lines indicate the range of forecasted 2023 corn yield potential by Aug. 23 based on average 2023 planting date at each location. Horizontal lines indicate the 25th and 75th percentiles of the yield distribution (associated with respective adverse and favorable weather scenarios during the rest of the season). The blue squares indicate the long-term (2005-2022) average yield potential at each location and the red dots represent the forecasted 2023 corn yield potential at sites that have already reached maturity. Separate charts are shown for irrigated corn (top) and rainfed corn (bottom).
Figure 4. Probability of the 2023 yield potential to be below (<10%, red color), near (±10%, yellow color), and above (>10%, green color) the long-term (2005-2022) average yield potential at each location. Separate maps are shown for irrigated corn (top) and rainfed corn (bottom). The larger a color section is within the pie chart, the higher the probability that end-of-season corn yield will be in that category.


Corn has already reached the dough stage across the majority of the Corn Belt, while dent stage (or even black-layer) has been attained in the southern fringe of the region. When compared to our previous forecasts, most sites in the eastern part of the Corn Belt have increased the likelihood of achieving near or above-average yields. Temperature and rainfall during the rest of August will likely determine the trend for the eastern fringe of the Corn Belt. Moreover, above-average yields are also expected at a few spots in NE, KS and northwestern MO.

In contrast, two regions, one in south-central NE and north-central KS, and the other in MO, eastern and northern IA exhibit a high probability of below-average yields.

Overall, the regional average yield this season is expected to be near the historical average (<1% yield deviation).

These forecasts do not take into consideration problems with stand emergence, hail/flooding damage, replanting situations, disease or nitrate leaching. In fields negatively affected by these constraints, actual yields will be lower than estimates provided here.

It is important to keep in mind that yield forecasts are not field specific and, instead, represent an estimate of average on-farm yield for a given location and surrounding area in absence of the yield-reducing factors mentioned here. Likewise, crop stages and forecasted yields will deviate from those reported here in fields with planting dates or hybrid maturities that differ markedly from those used as the basis for these forecasts. We will follow up with the final forecasted yield and analysis of the 2023 crop season in September.

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A field of corn.