Precipitation trends in the United States Corn Belt for the week ending on Sept. 23 were mixed. Rainfall for the week was mainly concentrated in the Dakotas, southwestern Minnesota, and into Iowa. While parts of northeastern Illinois also received about an inch of rain this past week, the rest of the eastern Corn Belt trended drier than normal.
Recent persistent drier trends have allowed for abnormal dryness and now some moderate drought conditions to return to Illinois, Indiana, and Ohio this month. For the Corn Belt as a whole, this was the eighth driest third full week of September in 30-plus years, according to data from WeatherTrends360. Temperature-wise, the week was warmer than normal across the growing region. However, the week started on a cooler than normal note across the eastern Corn Belt before much warmer than normal temperatures pushed eastward mid to late in the week and into the weekend.
Trends during the final full week of September, ending on Sept. 30, will be fairly similar to the previous week for the Corn Belt. Regionally, temperatures for the week will trend much warmer than normal while wetter precipitation trends are mainly expected in the same areas as last week, although cumulative amounts are likely to be lower.
According to forecasts from WeatherTrends360, this will be the eighth driest and eighth warmest final week of September in 30-plus years for the United States Corn Belt. Temperatures across the growing region will be above normal for the entirety of the week, with the largest departures from normal (up by 10° to 15° F) expected towards the end of the week and into the weekend.
Although persistent dry conditions have led to worsening drought throughout the summer across large portions of the Corn Belt, the drier conditions should also be more conducive for harvesting efforts that are now getting underway. According to the National Drought Mitigation Center, currently 58% of the United States corn crop is growing under drought conditions while an additional 25% is growing under abnormally dry conditions.
The amount of corn that has reached maturity and the amount of corn that has been harvested thus far is more than both the five-year average rate and the amount at this time last year. Early harvest efforts through September are likely to remain faster than last year and average.