1. On May 13, 1846, the State of Michigan approved the charter for what is now known as Central Michigan University. The institution's original name was the Central Michigan Normal School and Business Institute, and it was intended to offer teacher training and business courses.

2. May 13, 1955, saw the opening of the Mackinac Bridge, which connects the Upper and Lower Peninsulas of Michigan. At the time of its construction, the bridge was the longest suspension bridge in the world, and it remains a popular tourist attraction today.

3. In 1972, a series of severe thunderstorms and tornadoes struck Michigan on May 13, causing widespread damage and several fatalities. The storms are known as the "Super Outbreak" and are considered one of the most destructive tornado outbreaks in U.S. history.

4. On May 13, 1985, the first official Pure Michigan tourism campaign was launched by the Michigan Department of Commerce. The campaign has since become famous for its picturesque advertisements showcasing Michigan's natural beauty and inviting visitors to experience everything the state has to offer.

5. In 2019, a May 13 hailstorm caused significant damage in several Michigan cities, including Grand Rapids and Wyoming. The hailstones ranged in size from golf balls to baseballs, and many residents reported broken windows, dented cars, and other forms of property damage.