INDIANAPOLIS (WISH) — Whether you call them woolly bear caterpillars or wholly worms, many of us in the Midwest have heard about them. They are often associated as winter predictors, but is there any truth to these claims?

Folklore

There are multiple versions of the woolly bear caterpillar winter folklore. One of the easier versions to remember is that if the woolly bear has more black than brown color, a harsh winter is in store. A mild winter is predicted when there is a wider section of brown in the caterpillar.

Others attribute the positioning of the darker bands to the portions of winter that will be harshest. For example, if the black coloring is near the head, the beginning of winter will be harsh.

Another version of the folklore attributes the thickness of the caterpillar’s coat to the winter severity. A cold winter equates to a very woolly caterpillar.

Is there any truth to the folklore?

Unfortunately, the National Weather Service does not support these claims. The changes in coloring can be attributed more to the caterpillar’s feeding habits, age, and species.

Although folklore is fun to hear, there are better sources out there for a winter forecast. A more reliable source would be the NOAA winter outlook, which takes into account the current El Niño/La Niña situation.

You can read more about that outlook by clicking here.