Map: Central, Eastern Ontario Takes Brunt of August Dryness

The 2025 growing season has taken a sharp turn in parts of Ontario, with heat and dryness stressing corn and soybeans, particularly over the past month or so. 

As the map below shows, large parts of central and eastern Ontario received less than 40% of normal precipitation over the 30-day period ending Aug. 26. Areas east and west of Toronto fared better – although amounts were still below normal – while the deep southwest was near to above normal.  

Although now much cooler, persistent high temperatures earlier (many days over 30 degrees C, with humidex values up to and above 40 degrees C) added to the stress on crops. 

Eastern Ontario has been especially hard hit, with farmers reporting stunted growth, poor pollination, and shrinking yield potential, particularly in corn and soybeans during critical reproductive stages. In contrast, the deep southwest of Ontario has enjoyed near-ideal moisture all season, supporting robust crop development. 

According to Philip Shaw’s latest Market Trends report for Grain Farmers of Ontario, corn basis levels have risen sharply in recent weeks, particularly in eastern Ontario. Soybean basis values have also moved higher, he added 

“Clearly, with the drought in many parts of Ontario corn supply moving forward might be compromised,” Shaw wrote. “This could result in big basis opportunities for pricing in the next few months. However, it could also result in increased US imports of corn to keep prices low.”