Do woolly bear caterpillars predict winter weather?

By all accounts, October has been a spectacular year for foliage. At this writing, the trees appear to be in peak color, with most of our large sugar maples sporting bright yellow and orange coats with splashes of red. The red maples are shimmering scarlet, and green hickory leaves are slowly giving way to yellow shades hidden within. To date, we’ve had nice weekend weather and only one mildly frosty morning, which did little damage to the remnant plants in the vegetable garden.

I’ve been looking for signs that another change of seasons is upon us and wondering whether winter will be cold and snowy, wet and warm, or a combination of whatever winter may bring? The other morning, while heading to the barn for chores, a folklore winter season predictor literally crossed my path, or rather crawled along on its belly in front of me.

A woolly bear caterpillar, wrapped in a warm fuzzy cloak of black and rusty-brown bands was making good time through the grass, minding its own business and steadfast in its search for winter quarters. I picked it up, and it instantly curled into my warm hand.

I brought it inside and placed it under a glass until it relaxed and stretched out to full length. It was only 1.5 inches long with a long, rusty-colored band in its middle and shorter bands of black on its head and tail. Here was the clue I was looking for.

You may have heard the old folktale that the length of the woolly bear's rust- or black-colored bands are a predictor of winter weather, but I couldn’t remember, for the life of me, what these colored bands meant.  To help me determine what my woolly bear was predicting, I went to the experts – the National Weather Service! Certainly, they would provide the answer, and sure enough here is what I discovered, according to the National Weather Service’s website with a section devoted to woolly bear folklore.

How does the woolly bear caterpillar predict winter?

“According to folklore, the amount of black on the woolly bear in autumn varies proportionately with the severity of the coming winter where the caterpillar is found. The longer the woolly bear’s black bands, the longer, colder, and snowier and more severe the winter will be. Similarly, the wider the middle brown band is associated with a milder upcoming winter. The position of the longest dark bands supposedly indicates which part of the winter will be the coldest or hardest. If the head end of the caterpillar is dark, the beginning of winter will be severe. If the tail end is dark, the end of winter will be cold.”

But according to the National Weather Service, there is more to the woolly bear’s prediction abilities. The "woolly bear caterpillar’s coat will indicate the upcoming winter’s severity. So, if its coat is very woolly, it will be a cold winter.”

Not only the length of the woolly bear coat, but also the caterpillar’s direction of travel is a predictor. “It is said that woolly bear’s crawling in a southerly direction are trying to escape the cold winter conditions of the north. On the other hand, woolly bear’s crawling on a northward path would indicate a mild winter.”

Confused yet? For the complete article, here is a link to the NWS website section on woolly bears.

What is Connecticut's woolly bear winter prediction?

I took a picture of the woolly bear I captured last week, and it clearly shows a much longer rusty-colored middle band indicating a milder winter. But then again, the one I found was traveling southward meaning a more severe winter, and while I am not an expert on the length of a woolly bear’s coat, this one certainly looked like it is very woolly.

So, there you have it folks, according to the woolly bear in my yard in Putnam, this will be a mild winter. At least, that is, if the size of the bands is more important than the direction of travel and woolliness of the coat. To make sure I was reading the signs correctly, I checked the other reliable predictor of winter weather – the Old Farmer’s Almanac.

Like the Nation Weather Service, the Old Farmer’s Almanac also reports the longer the middle rust-colored section, the milder the winter. Other interesting information from Farmer’s Almanac included two annual celebrations of the infamous woolly bear.

Spend some time outside: Conn. sights, sounds and events to look for in October

“For over 40 years, Banner Elk, North Carolina, has held an annual Woolly Worm Festival in October, highlighted by a caterpillar race. Similarly, there is a Woolly Bear Festival that takes place in Vermilion, Ohio in early October.” Sounds like fun, especially the caterpillar race.

After examining my woolly bear caterpillar, I placed it among the leaf litter in the flower garden. I hope it snuggles down among the leaves, protected from frost and snow, to ready itself for springtime.

One thing we can rely on, no matter the size of the bands on the woolly bear, is that the Winter Solstice is Dec. 21 at 4:48 p.m. and winter will be with us until the Vernal Equinox March 20. I guess we’ll just have to wait and see if my woolly bear prediction of a mild winter is true. What I do know for certain is that, come spring, my caterpillar will emerge from its winter home as the Isabella tiger moth.

We live in a beautiful place called The Last Green Valley National Heritage Corridor. Each day of every month and every season brings another reason to be amazed at the splendor right outside our door. This is so true during October. I hope you’ll join me, and together let us enjoy it, care for it and pass it on.

Bill Reid is the chief ranger of The Last Green Valley National Heritage Corridor. He can be reached at 970-774-3300 or bill@tlgv.org.

This article originally appeared on The Bulletin: Opinion: Woolly bear caterpillars predict CT winter