Ag Weather Forum

May Weather Challenges Record Corn Yield Prospect

Bryce Anderson
By  Bryce Anderson , Ag Meteorologist Emeritus
Connect with Bryce:
The month of May 2023 was the 11th warmest on record in the contiguous U.S., with precipitation ranking in the driest one-third of the historical record. The warm and dry trend dominated conditions in the top 5 corn producing states as well. (NOAA graphics)

A look at the NOAA National Centers for Environmental Information (NCEI) report for the month of May in the top 5 U.S. corn production states suggests that the USDA projection of a record corn yield in 2023 could be a tall order. That yield figure is 181.5 bushels per acre (bpa).

The USDA World Agricultural Supply and Demand (WASDE) report on June 10 had this qualifying detail for that projection: "The yield projection is based on a weather-adjusted trend, estimated using the 1988-2022 time period, assuming normal planting progress and summer growing season weather."

The top 5 states in U.S. corn production in 2022 lined up as: Iowa; Illinois; Minnesota; Nebraska; and Indiana. Total corn produced for grain from these states in 2022 came to 8.64 billion bushels (bb), 63% of the total U.S. corn-for-grain production of 13.73 bb. (Numbers compiled from the USDA/NASS annual crop production report issued in January 2023.) How these top states fare weatherwise is obviously key to the national corn crop size.

May of this year featured weather conditions in those top 5 corn states which were not matched in previous U.S.-record corn yield years going back to 2009. May of 2023 saw near-average temperatures in Indiana, but above- to much-above-normal temperatures in the other four top production states. Minnesota, in fact, had its fourth-warmest May on record. Nebraska, Iowa and Illinois also recorded above-average temperatures for the month.

On the other hand, precipitation in these top 5 states was mainly below average in May. Iowa, Illinois, Minnesota and Indiana ranked in the driest 10% to 25% of the historical record. Nebraska's May precipitation total was the exception, ranking above average.

The past 15 years of U.S. corn production had record yields set in 2009 (164.7 bpa), 2014 (171.0 bpa), 2016 (174.6 bpa), 2017 (176.6 bpa), and 2021 (176.7 bpa). The record-yield years cited did not have the warm and dry conditions in May to start out the growing season. The temperature trend is especially noticeable. In 2016, Minnesota had above-average temperatures in May. That is the only occurrence of a warm condition relative to average in the top 5 corn production states in a recent previous year when U.S. harvest yields marked a new record.

The 2023 corn production season still has a long way to go. We're just into the first half of the first month of summer. However, the 2023 U.S. corn crop is already starting out with challenging conditions, giving plenty of room for doubt about the ability of this year's crop to even match the standards set by previous years, let alone put a market in the 180-plus bushels per acre territory.

Bryce Anderson can be reached at


To comment, please Log In or Join our Community .