Extreme weather events have multiple adverse effects, with sectors like agriculture being particularly vulnerable to their impacts. Changes in weather extremes in eastern Ontario from 1961 to 2010 were investigated by assessing trends in extreme event indicators. In addition to generic and agroclimatic indicators, corn- and soybean-specific indices were developed, accounting for crop tolerances to extremes at different growth stages. A shift to a warmer, wetter climate and increases in accumulated heat units and growing season length were observed. Flooding during soybean planting season and early stages of corn development became more prevalent. Additionally, increases in drought events during critical reproductive stages were recorded for both crops. The most significant changes occurred in areas where key agricultural lands are located. The results of this research will help to identify opportunities and threats to crop production, make informed decisions on modifying agricultural practices and develop tools to support adaptive policy development.