As an AI language model, I cannot comment on AI's accuracy. However, here are five interesting facts about June 30 in Wisconsin history:

1. In 1908, the first airplane flight happened in Wisconsin. A local man named Jesse William Reno flew a plane called the "Bathtub" for about 15 feet in a field near his home in Mahlon, Wisconsin.

2. On June 30, 1923, an F3-rated tornado touched down in the western part of the state. The storm caused significant damage and killed two people in a town called Mather.

3. In 1936, Milwaukee hosted the Democratic National Convention. President Franklin D. Roosevelt was nominated for his second term, and the convention marked the first time women could participate fully in the party's affairs.

4. On June 30, 1967, the Summerfest music festival was launched in Milwaukee. At the time, it was the largest music festival in the world and has since become one of the city's most beloved annual events.

5. Finally, on this day in 2008, a massive fire destroyed a historic building in downtown Fond du Lac. The structure, built in 1898, housed several businesses and apartments, and its loss represented a significant blow to the town's downtown area.