Every summer Dixon holds the annual Petunia Festival, featuring a parade, carnival, country concert, fireworks show, runners road race, and other various activities.

The Petunia Festival was conceived after the Dutch Elms Disease wiped out the elm along Galena Avenue in the late 1950s. In response to the dramatic change the streetscape underwent, the Dixon Noon Lions Club first started planting petunias to regain some sort of streetscape identity once again to Galena Ave in the early 1960s. Before the festival, volunteers plant petunias all along the main streets, especially along Galena. The flowers are watered and maintained by the combined efforts of city workers and volunteers. Pink petunias are predominant, but purple and white ones, the colors of the local high school teams, the Dixon Dukes and Duchesses, are also planted.

The parade features a multitude of floats from surrounding businesses, politicians, and other area groups. A carnival is also held in Dixon during this time, and the festival ends with the Fourth of July fireworks set off on the banks of the Rock River.