The WZZM 13 Weatherball is a steel structure which gives basic visual information about the upcoming weather. The original weatherball, installed in 1967 was a a 64-ton, 125-foot-tall structure perched on top of the Michigan National Bank building in downtown Grand Rapids. The colors it displayed were representative of the coming weather pattern. A poem was written about the weatherball's colors:
Weatherball blue, cooler weather in view.
However, due to questions about its stability it was removed in 1987, after 20 years of existence. WZZM located the weatherball, which had resided in a Kalamazoo junkyard since its removal, and purchased it in 1999. In 2002, plans were announced to refurbish the stainless steel ball, and add new neon lights. The weatherball was perched on a 100-foot (30 m) monopole, and was lit on May 7, 2003. It is visible from both Interstate 96 and U.S. Highway 131, the two major freeways in the area.
Shortly after the reintroduction of the WZZM 13 Weatherball, a contest was held where viewers submitted video recordings of songs to coincide with the meanings of the weatherball. The winner chosen had their song on a new commercial that aired to inform the viewership of the significance of the colors.
The station also has a costumed character mascot of the Weatherball named "Blinkie". A similar weatherball is also located on the Citizen's Bank building in Flint.
In the 1980s, a jocular addition to the poem was popular:
Weatherball black, nuclear attack.
Pins and t-shirts were made displaying this addition.