Nature's meteorologist? Do woolly bear caterpillars forecast winter weather? What to know

Want to know how bad this winter is expected to be?

You could look at the long-term NOAA forecasts for Ohio, or to the meteorologists at the National Weather Service, with their fancy technology, like radar, their historic data, like when Ohio sees its first snow on average, and their forecasting ability, such as how La Niña might affect the Buckeye State this winter.

Or you could turn to the humble woolly bear caterpillar.

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Do woolly bear caterpillars forecast winter weather?

Woolly bears (or woolly worms in the South) have a reputation for forecasting the coming winter weather, according to the Farmer's Almanac.

The caterpillar has 13 segments, and is often brown in the middle and black at both ends. According to the almanac, the wider the brown sections are, the milder winter will be. The more black showing on the woolly bear, the harsher the coming winter will be.

And the woolly bear's forecasting ability is said to go further than that. If the black band of the caterpillar is wider by the head, the beginning of winter will be severe, according to Buckeye Yard and Garden Online, a publication of the Ohio State University Extension. And the reverse is said to be true if the black band is wider by the tail end.

How did woolly bears gain their reputation for winter predictions?

According to the Farmer's Almanac, Dr. C. H. Curran, curator of insects at the American Museum of Natural History in New York City, made the woolly bear caterpillar famous through a series of experiments he began in 1948 that were publicized in the New York Herald Tribune newspaper.

Curran and his wife traveled to Bear Mountain State Park, about 40 miles north of the city, where he collected as many woolly bears as he could find in a day, per the almanac. He averaged the number of reddish-brown segments on each, then forecast the coming winter weather through a reporter friend at the Herald Tribune.

He continued the experiment for eight years, and the resulting publicity made the woolly bear one of the most recognizable caterpillars in North America (alongside the monarch caterpillar and tomato hornworm), the almanac states.

National Weather Service debunks woolly bear forecasting abilities

Of course, the National Weather Service has come along to pooh-pooh the woolly bear's winter foresight, with its science and facts.

According to the NWS, the caterpillar's coloration is the result of how long it has been feeding, age and species, as well as how many times it has molted.

The better the growing season, the more woolly bears will eat and the bigger they will grow. This results in narrower brown bands in its middle. Woolly bears also molt six times before reaching their full size. With each molt, they become less black and more reddish-brown.

Also, there are about 260 species of tiger moths (the adult of the woolly bear caterpillar) in North America, according to the NWS, and each species has slightly different color patterns and hair coverings. As a result, some of the color and hair variations that we see in woolly bears each fall are a result of these different species.

And, the Farmer's Almanac adds that Curran knew his experiments in the late 1940s and early '50s wouldn't hold up to scientific scrutiny. They were an excuse to have fun, get away from the city and see some fall colors.

Woolly bear festivals held in Ohio, North Carolina

The woolly bear is celebrated during at least two festivals in the United States.

In Vermilion, Ohio, on the shores of Lake Erie west of Cleveland, the Woollybear Festival (spelled as one word) happens each fall. The 52nd annual festival happened on Sept. 29 this year.

The festival is the creation of Cleveland meteorologist Dick Goddard, who founded the festival in 1973. It features a costume contest, caterpillar race and "Wonderful, Wacky Woollybear Parade," according to the Vermilion Chamber of Commerce.

And, Banner Elk, North Carolina, hosted its annual Woolly Worm Festival on Oct. 19. It was the 47th annual event.

This article originally appeared on Cincinnati Enquirer: Can woolly bear caterpillars predict winter weather? Here's the truth