Woolly Bear Caterpillar Forecasts Winter Weather [Video]

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The National Weather Service announced the winter forecast, for the United States. For the most part, between the 2018-19 season, will be warmer for some regions and colder for others.

The Old Farmer’s Almanac offers this report:

Snowfall will be above normal in the north and below normal in the south, with the snowiest periods in late November, late December, early and late January, mid- to late February, and early March. April and May will have temperatures below normal in the north and above normal in the south and will be slightly drier than normal.

Predicting the weather is a science. Meteorologists use “physics, supplemented by statistics, empirical techniques,” according to Encyclopaedia Britannica. However, many amateur weatherpersons turn to a caterpillar’s coloration to determine winter’s harshness each year.

woolly bearIn Portland, Oregon, the reporter told viewers they did not have to take his word for a warmer than normal winter, they should consult the Woolly Bear Caterpillar for further evidence. In the video he shared, the little insect’s rust band was much larger than either of the black. This supported his prediction.

It is not an uncommon phenomenon to hear people trust the woolly bear for their weather forecast. Based on the old wives’ tale or common folklore, observing this caterpillar’s appearance is an excellent predictor. Several characteristics of the woolly bear are used, including the thickness of its coat, and the width of the black and brownish-red or rust bands of color. Woolly bears are black on either end and rust in the center.

According to those who postulate the wooly worm’s ability to forecast the season each of their 13 segments represent the 13 weeks of winter. So, if the coat is thick there will be snow. If the reddish-brown band is narrow, then the season will be harsh. The wider it is the milder the weather.

Central Illinois resident Judy Fraser uses nature’s clues when she forms her predictions for the upcoming winter. Her list includes persimmons, squirrels, leaves, and wooly worms. For the past 30 years, she has shared her weather forecast on WCIA News in Champaign, Illinois with an 80 percent accuracy rating.

Fraser reports the wooly worm forecast indicates 2018-19 will be an equal opportunity winter:

  • Mild at the start but frequent and serious cold shots late.
  • Keep the shovels handy but it will not be a big year for snow.

Woolly Bears Climb to Fame

According to WCIA, using the caterpillar to predict the winter season according is a century’s old custom in the Blue Ridge Mountains. The custom began when European settlers were taught to read the wooly worm’s coat by Native Americans.

Their climb to fame started in the fall of 1948 when the curator of the American Museum of Natural History in New York City set out to prove the Woolly Bear did, in fact, reveal they were accurate forecasting tools. He gathered as many woollies as he could during a trip to Bear Mountain, 40 miles north of the city.

Dr. C. H. Curran measured the lengths of black and rust segments on each worm. Using the average of those numbers he created a forecast, which thanks to a friend at The New York Herald Tribune was published.

Over the next eight years, Dr. Curran continued his experiment determined to “prove scientifically a weather rule of thumb that was as old as the hills around Bear Mountain, according to The Old Farmer’s Almanac.

As a result of the publicity, the woolly worm became the most recognizable caterpillar in North America.

woolly bearHe, his wife, and other believers formed The Original Society of the Friends of the Woolly Bear after Curran’s experiment appeared to legitimize the folklore. Thirty years after the society last met, The Trailside Museums and Zoo at Bear Mountain State Park acknowledged Dr. Curran’s work and began to keep a record of yearly counts they sponsor.

The caterpillar’s popularity gave birth to festivals honoring them. Since 1973, the Woolly Bear Festival has taken place in Vermilion, Ohio. The residents hold a parade, woolly bear races, and an official forecast for the upcoming winter.

During the weekend of October 20-21, 2018 Banner Elk, North Carolina held its 41st Annual Woolly Worm Festival.

Other festival locations include:

  • Beattyville, Kentucky; since 1987.
  • Lewisburg, Pennsylvania; began in 1997.
  • Oil City, Pennsylvania; since 2008.
  • Lion’s Head, Ontario, Canada; began in 2011.

Woolly Bears Are Found in Southern Canada and the United States

woolly bearThe banded woolly bear or woollybear is also referred to as the woolly worm in the Southern U.S. Yet another name is the Hedgehog Caterpillar because it curls into a tight ball and “plays dead” when disturbed.

Like all caterpillars, they are hatched in warm weather from an egg laid by a Pyrrharctia isabella; the Isabella Tiger Moth. Mature woolly bears search for overwintering sites under bark or inside cavities of rocks or logs.

The National Weather Service explains:

They are often found in the autumn after they have left their food plants, [a] variety of grasses and weeds including plantain, dandelion, and nettles, in search of a dark and sheltered spot where they can hibernate as larvae for the winter.

When spring arrives, they spin cocoons and after their transformation, they emerge as full-grown moths.

Written by Cathy Milne-Ware


National Weather Service: Woolly Bear Caterpillar – Winter Predictor Or Not?
Wonderolpolis: Can Woolly Worms Predict the Weather?
WCIA News: 2018-2019 Wooly Worm Forecast
Woolly Worm Festival: Website

Featured Image Courtesy of Nicholas D.’s Flickr Page – Creative Common License
Top Image by Micha L. Rieser Courtesy of Wikimedia – Creative Commons License
First Inset Image Courtesy of Mary Meyer’s Flickr Page – Creative Commons License
Second Inset Image by Paul M. Welsh Courtesy of Wikimedia – Creative Commons License
Third Inset Image Courtesy of Mike Keeling’s Flickr Page – Creative Commons License


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