Summer Weather Forecast: What Farmers Can Expect for Growing Season

Read Time: 4 minutes

by John Mioduszewski, Environmental Data Scientist, Bayer Crop Science

June 9, 2020


To listen to a videocast version of the growing season forecast, click here.

One of the major weather stories over the spring was a couple of highly unusual cold weather outbreaks in most of the United States east of the Rockies after a warm March. More recently, many fields in the Midwest have received a lot of rain — but I think most farmers would agree that it’s been a big improvement from the widespread washouts we experienced in 2019. 

Now we’re turning our attention to the outlook for the growing season, including a few things to keep an eye on for summer. 

What is the Impact of Spring Cold Snaps? 

We experienced below-average temperatures in the Midwest in April and early May with two severe outbreaks of Arctic air — one in mid-April and another in the second week of May. The latter brought an extremely unusual hard freeze to much of Ohio, southern Indiana and eastern Kentucky. The remainder of the Corn Belt experienced freezes on multiple mornings from May 8 to May 13, in some places as cold as the low-mid 20s. Overall, we’ve seen limited reports of crop damage, which seem to be more pronounced in wheat, vegetables and tree fruits. A few areas were hit pretty hard and had to replant corn and soy acres, but those crops are unlikely to have any major lasting effects on yield.

Now into June, it would be extremely unlikely to see temperatures below 40 degrees, even in the upper Midwest. We still would like to see some more warmth in the coming weeks to help speed early crop development, and that is likely to happen.

Average Temperature Departure from Mean
April 2020
(Source: Midwestern Regional Climate Center)
Date of Last 32° Freeze
May 2020
(Source: Midwestern Regional Climate Center)

What to Expect for June Weather 

After a warm and dry start to June in most areas, there is no clear indication from the current data about what the rest of the month will have in store for us. In that situation, it’s unlikely that we’ll see extremely hot temperatures in June that might affect crop health. For precipitation, we’re setting up to be in pretty good shape in the Midwest as far as drought conditions. Unfortunately, farmers in western Kansas and eastern Colorado are well aware of their locally severe drought conditions, and it’s never good to be getting into the summer already in a water deficit.

June Temperature Outlook
(Source: NOAA)
June Precipitation Outlook
As of May 31st (Source: NOAA)
For precipitation, we’re setting up to be in pretty good shape in the Midwest as far as drought conditions.

Tricky Summer Weather and the Continued Effect of Wet Soils 

Historically, El Niño — a warming phase of the waters in the central and eastern Pacific near the Equator — has significant forcing on summer weather across the central states. An El Niño during the summer, for example, tends to keep the temperature cooler and reduces heat stress on crops. But this year, El Niño is in a neutral phase, and that makes long-range summer forecasting more difficult. In addition, there are some conflicting signals in the seasonal forecast that make this summer’s forecast lower confidence than normal. But overall, it is likely that temperatures and precipitation shouldn’t deviate too far from normal.

One thing we know for sure is that soil moisture is still high almost everywhere, with large areas still above the 90th percentile. That’s an important factor, as increased soil moisture tends to feed back to the atmosphere, increasing humidity and sometimes rainfall. So that could result in above average precipitation and potentially slightly cooler daytime temperatures into the summer, but nothing so far is pointing toward an extremely wet summer. 

Calculated Soil Moisture Ranking Percentile
June 2020
As of June 8th (Source: NOAA)

One issue resulting from the wet soils and above-average rainfall is the possibility of increased fungus threats. This is especially true for farmers in the Southeast, the lower Mississippi Valley, and also in the Ohio Valley, who have had rounds of heavy rain in recent weeks and above average soil moisture levels for a long time that could potentially increase the need for fungicide applications. 

Trusted Resources to Keep an Eye on the Weather 

I want to also remind you of a few helpful resources and tools for tracking the weather as it relates to farming: 

  • Midwest Regional Climate Center - This service provides accurate weather data and regional weather information across the Midwestern states. 
  • Climate FieldView™ - If you have your fields mapped in FieldView, you can access field-level precipitation data, historic precipitation, as well as the upcoming forecast, all from your desktop, phone or iPad®.  
  • USDA Weekly Weather and Crop Bulletin - The USDA’s weekly report for weather and crop updates.
  • NOAA - The National Weather Service falls under NOAA and is a great source for historical weather data, weekly forecasts, as well as weather safety and education information. 

Thanks for reading and best of luck this summer!

About the Author

John Mioduszewski is an environmental data scientist at Bayer Crop Science, working at the intersection of weather data and plant breeding. Prior to joining Bayer, John was a postdoctoral researcher at the University of Wisconsin – Madison studying Arctic climate change. John holds a PhD from Rutgers University and a bachelor’s from Edinboro University of Pennsylvania.