Woolly Bear Weather Prediction
"No winter lasts forever; no spring skips its turn." ~ Hal Borland
The Isabella Moth Caterpillar
As winter is quickly approaching, we are seeing more Isabella tiger moth caterpillars. These insects are often referred to as the woolly bear, banded woolly bear, woolly worm and the black-ended bear.
According to folklore, the woolly bear caterpillar can predict the severity of the coming winter. The more black bands the critter has the harsher the winter conditions will be. So, if you love cold snowy winters, you want more black bands.
How Does the Woolly Bear Predict the Weather?
The average woolly bear caterpillar has 13 segments. They can be easily identified in the above picture. Each one of these segments symbolizes one week of winter. The brown segments represent a mild week, and the black segments represent a harsh week. If the head area has more, then the beginning of winter will be the harshest. If the rear area has more, the end of winter will be the worst.
The thickness of the caterpillar’s hair is also an indication of the upcoming winter conditions. If it is dense, the winter will be colder. If it is sparse, the winter will be mild.
Giant Leopard Moth Caterpillar
A caterpillar often mistaken for the Woolly Bear is the giant leopard moth caterpillar. However, this caterpillar is completely covered with black hair and has red spiracles and inner segments. Every year, people get nervous when they see this caterpillar. They believe the winter is going to be horrible because the caterpillar is completely black with no brown.
The Vermillion Woolly Bear Festival
Woolly bear caterpillars are very popular in Ohio. So much so, the residents of Vermillion have held an annual “Wooly Bear Festival” since 1973. This year they help it on October 10th. Somehow we missed it!!! Well, maybe we will catch it next year.
This Woolly Bear Festival usually lasts one day and includes a winter forecast, parade, and even woolly bear races.
Science or Folklore?
How accurate are the woolly bears at weather predictions? Not very accurate at all. Scientists have performed studies and have found out that the caterpillars’ bands are affected by other factors. These include the species, food source, natural conditions and age.
Just because there is no scientific evidence that the Woolly Bear caterpillar can predict the weather, does not mean they cannot. As many of us nature lovers know, animals and insects seem to know what is coming before we ever do.
If you want to believe in the folklore or not, is completely up to you. It does not hurt to check out the caterpillars and see what they might be telling us. Maybe they will be right. This year the caterpillars I have found all have a large brown section. Here is to hoping for a mild winter.
2021-2022 Woolly Bear Winter Prediction
The caterpillar pictured directly above have 13 segments, 7 are black and 6 are brown. There are 4 dark stripes on the front end of the caterpillar and 3 on the rear. So, compared to the 5/5.5/2.5 ratio from last year, the beginning and middle of winter should not be as bad this year. However, the weathermen are predicting this winter will be worse.
Many of the other Woolly Bear caterpillars we have seen this fall did not have dense hair and seemed to have more brown. These are both indications that the winter will be mild.
The last caterpillar pictured is from October 2021. It is not the same caterpillar as the ones pictured above it.
So, does their coloring change due to their diet or the upcoming winter? I guess we will have to wait to find out.