What a Woolly Worm Knows

How to Read a Woolly Worm

Oct 2, 2017
Woolly Bear Caterpillar by SillyPuttyEnemies
SillyPuttyEnemies / Wikimedia Commons

Share: 

Rate this Post: 

Average: 3.6 (87 votes)

It’s time again to shine the spotlight on a certain caterpillar—the woolly worm! According to folklore, this fuzzy fellow has the ability to predict the weather.

Also called the woolly bear caterpillar, the banded woolly bear, or just woolly worm, he’s the larva of the Isabella tiger moth (Pyrrharctia isabella).

In terms of appearance, the caterpillar has segments of either rusty brown or black. Often, he is black on both ends with rust-colored segments in the middle, although he might be almost all black or all rust.

Folklore says that if the rusty brown band is wide (more segments), then it will be a mild winter. The more black there is, the more severe the winter. 

Note that white, yellow, or other colors of fuzzy caterpillars are NOT the same type of woolly worm and are not used for weather forecasting. We’ll leave the weather-prognosticating “skills” to your own observation!

Learn More

For more woolly worm fun, check out the Woolly Worm Festival in Banner Elk, North Carolina. At this annual mid-October event, woolly worms race up to the top of their 3-foot-long strings, accompanied by thousands of cheers. The bands of the winner predict the coming winter.

Is there any real science behind the woolly worm’s predicting power? Find out here!

Watch a short video about the woolly worm:

Have you seen a woolly worm in your area? What did it look like? Feel free to share your experience in comments below!

About This Blog

Your Old Farmer's Almanac editors occasionally share our reflections, advice, and musings—and welcome your comments. too.

Reader Comments

Leave a Comment

Wooly bears

I’ve seen several wooly bears this year. All black and very large. Not a good sign.

Wooly Bear today

ours is short and very dark, took a video and some pics, wish I could share with you . he was crawling in the grass

Solid black Woolly worm fat

Yes this evening in christiana tn on porch big fat solid black Woolly worm

All Black Wooly Bears

My husband and I have been seeing all black wooly bears. We have always watched to see what their color is like each year and they have usually been spot on. This year is scary. We live in NE PA.

Big fat all black wooly caterpillars

Just seen the biggest, wooliest, all black caterpillars I have ever seen. Several here in Scottsville Ky have been spotted. Hmmm? Everyone tells me going to be a bad winter!

All Black Wooly

Just found an all black wooly this evening- Greensboro NC

Lucasville Ohio

I have seen six of these the past month and all have been large and all black. Let’s we if we have a bad winter here in Ohio. It’s 75 degrees today. Just seen one out on the outside wall.

Wooly worms in southeast Nebraska

I had a large, all black one on my front porch this morning. I'm heading south this winter! Ha!

Solid black

Don't head for Georgia! I just found an all black one on my carport. Plus, the persimmons are showing spoons, which is also an indicator of a bad winter.

Black Wooly worm

I believe Columbia, KY is going to have some severe weather this year. I have seen numerous large very fat, black all over, wooly worms on my patio. I've always heard the myth about them predicting winter and they've never been wrong before.

Black wooly bear

Seen all black one by a tree in my moms yard so thinking a bad winter tyrone,pa

Woolly Bear Caterpillar in all BLACK

My puppy Zoe was barking like crazy yesterday. She found a Woolly Caterpillar.
It was a big one and all Black. I believe here in Garnet Valley PA we are going to get a cold, Icy, Snowy winter

Woolly Worms

There are a lot of caterpillars in Boswell, Pa. it looks like a mild winter up here because there are a lot of all rusty brown Woolly Worms!!

All black woolly worm

I just saw an all black woolly wom today in Massillon, Oh, 10/30/2017

Woolly Bear Caterpillars

If one is all black does that mean a bad winter?

Wooly worms

I saw one just now on my porch, and it was solid black. We've mild winters, here in Western PA, I guess that's over

Wooly worm caterpillar

We saw one today with 3/4 rusty color. Let's hope he is a good weather forecaster. Guelph Ontario.

wolly Caterpillar

i saw four in just the last two or three days and they all had lots of rust color and very short black on both ends. guess mabey its going to be a mild winter here in elmira ny., the southern tier area! im good with that.

Wooly bear

Here in middle of Iowa, completely all blsck

Woolyworm

I live in wolf summit,West Virginia. We saw one today that was mostly rusty color only a small band of black.

Wooly worm

Saw all black wooly worm today and yesterday.

Half-Brown and Half-Black Woolly Bear Caterpillar

does a half brown and half black woolly worm mean a average winter for here in Columbus, OH

Wooly Bear

Mostly black w/small rust band (in middle) in mid Michigan.

Wooly Bear

I saw one a week ago and it was totally black. I had to take pictures. I haven't seen one in a very long time.

Wooly worm

I too seen an all black one here last week.
We live in Defiance, Oh

Wooly Worm

2 HUGE all black wooly worms in Lancaster, OH. Looks like Ohio is in for it this winter!

Wooly bear

Total black in Albany NY

Wooly bear

Saw one that was all rust colored here in CT. Wonder if due to our mild fall.

wooly bear festival

Oberlin, Ohio (northwest of Cleveland, OH already had their WoolyBear festival the first weekend of October, but I noticed nothing was mentioned of it on this site. It is hosted by weatherman Dick Goddard. He has hosted it for over 50 years.

Wooly worms

I have a question. My question is why do I/we see the worms cross over to other side of road?

Why Did the Woolly Worm Cross the Road?

In their search for the perfect place to hibernate, woolly worms will crawl far and wide. Usually this just means across a field or in a forest, but if a road happens to be there, they’ll cross that too! Alternatively, they could be attracted to the warmth of sun-lit asphalt. 

So, why did the woolly worm cross the road? Well, probably just to get to the other side.

Governor's Island

I went to the island in NYC harbor September 28th and so hundreds of them at the very end of the island. So glad I now know what I was looking at that beautiful day!

wooleys

Dont think I have ever seen one. Do they live on the west coast?

West Coast Woolly Worms

Woolly bear caterpillars (Pyrrharctia isabella) do occur on the west coast, however they are much more commonly seen in the east and midwest. 

Wooly Worms

Seeing just one solid black wooly worm would not be enough to make me think it would be a bad winter, seeing more than one would. I also check mid October for more accurate readings too. More often I rely on animal coats than worms, but that's just my take.

Wooly bear

Just saw the second one in northern Wisconsin completely copper color maybe we don't have to put up fire wood .this here

Woolly worm

Yes I saw a woolly worm on my porch the other day it was all black. Does that mean a bad winter here in Franklin Kentucky.

More evidence to collect...

My son and I have been taking wolly photos starting this summer to test this theory. So far, only three sighting. The first had lots of black, it was observed in June (midatlantic region). The second sighting was in August, had equal amounts brown and black. The third, and most recent was nearly all brown! I cannot tell what this means until we gather more specimens, lol. Nothing like teaching the scientific method via wolly bear!

Willy bear

I seen one yesterday on the foundation of my house, his brown band was very wide , and I hope that he's right and the winter is mild , so far the fall season is starting out very warm in Massachusetts.

Mild winter might be true!

The most recent wolly bear I observed was also nearly all brown. I am in the midatlantic and it still feels like summer. Good luck!

wooly worms and their colors predicting winter

i have not seen any yet as of today oct 11th. living in northern illinois (southern chicago suburb). hmmmm!

Wooly Worms

What does it mean when the wooly bear is white?

Old wives tales, Winter edition

I'm over a half of a hundred and have heard ALL my life different tales about weather predicting. Being from south Alabama, there are literally hundreds if not thousands of these prediction methods. The one that is forefront in my old feeble mind is the one about squirrels. If squirrels build their nests high in the tree, it's going to be a mild winter. The lower they build them, the more severe the winter will be. It's been my experience that of all the tales I've heard, this one is closer to the truth than any. Well, there is that one about persimmon seeds and cutlery or something like that.........

Wooly caterpillars

I live in St Louis, MO and I have noticed a lot of big, extremely wooly black caterpillars this fall.

ALL BLACK WOLLY WORMS

I saw an all black wolly worm the other day .. than I saw another one.. I stopped working in the yard

Woolly Bear sighting

I live in Churchville, which is in Western NY. Have seen a woolly bear caterpillar with a large orange band this week, October 4, 2017. We are experiencing a warmer than average fall here.

woolly worms

I saw a soild black one in my yard the other day, didn't think much about it till I saw another black one in the woods awhile ago.

Black woolly

This morning found a black woolly in my yard before heading to work. Live in Anne Arundel County, Maryland.

Woolybear Sighting

Saw a wooly worm, ie, wooly bully yesterday in Lyons, Texas. It came out from under a lawn mower my husband moved in the middle of the day. Guess it was taking a nap where it was cool since it was almost 90 degrees. Mostly rusty brown. I got a video of it scooting across the driveway until a gust of wind came and blew it away. I laughed out loud. I remember them as a small girl growing up in the country. Memories.

black wooly worm

found it on the sidewalk, it was all black. in Seneca Mo.

Wooly Worm March 19, 2017...last day of winter

I saw a wooly worm crawling on my porch this morning...are they supposed to still be out and about? Is he looking for a place to spin a cocoon? He was mostly the orange color in the middle, not much black on the ends. We definitely had a mild winter here in SE Kansas...although last week got below freezing at night!

Although it is probably

Although it is probably uncommon to see an active woolly worm in late winter in your area, the mild temperatures could have tricked it into coming out of hibernation. Over winter in cold climates, the caterpillars hibernate in sheltered areas, such as in leaves or under logs. The larvae have a chemical that keeps the interior of vital cells from freezing; the rest of the body, however, does freeze solid. When the weather warms, the caterpillar thaws out, then spins a cocoon and eventually emerges as a moth. So, your woolly worm might have indeed been looking for a place to spin a cocoon.

black wooly in February 2017

I found an all black wooly in my driveway this morning. It is February in Massachusetts. It has been below 40 here this past week or so. this morning only 22 degrees. what does this mean?

Found a Woolly Worm

Found one January 31st on the sidewalk outside. Is this typical?

woolly worm

In Minnesota!

one special woolly worm

Thank goodness that worm has a wool coat to help keep it warm! Just kidding. Actually, it is probably uncommon to see an active woolly worm in winter in your area, unless perhaps you’ve had a span of unusually warm temperatures. Over winter in cold climates, the caterpillars hibernate in sheltered areas, such as in leaves or under logs. The larvae have a chemical that keeps the interior of vital cells from freezing; the rest of the body, however, does freeze solid. When the weather warms, the caterpillar thaws out, then spins a cocoon and eventually emerges as a moth.

Wooly Worm

My mom just found one on the floor near her desk. She was cleaning up and thought it was just a piece of fuzz on the floor, but when she went to pick it up it curled up. She scooped it into a piece of paper and through it outside. We love in North Florida.

Saw my 1st Woolly Worm 3

Saw my 1st Woolly Worm 3 weeks ago-- All Black so in Kansas City, KS I'm expecting a Hard Winter-- Yes I believe in the Prediction!!!

I saw something about 4 in

I saw something about 4 in long and solid black inside my ground floor condo today. SCARED me to death. HOPE it was a catipillar vs about any other kind of creature. THE critter is still at large....

FROM Atlanta

OMG! Did you call 911? LOL!

OMG! Did you call 911? LOL! Is it still lurking around your home? Would love to see a picture of it. If you see it again, throw a bowl over it, slide something underneath and walk that monster to the door as fast as you can! ;) Good luck.

Wooly Caterpillar

Looked and looked but couldn't find any. Finally, one was crawling on the driveway today. Only Jan, Mar, Apr and Oct were black. All the rest of the caterpillar was golden brown. YEAH

wolly-buggers

Only recently [past couple weeks] have I seen any of these and most have been dead; one was lethargic. We are experiencing a lengthy dry spell and perhaps this is affecting them. Most have been black; one had a small band of brown in the middle; and I saw one cream color .... all but the lethargic black one was dead. A friend said a friend of hers [Virginia, Pennsylvania areas] commented there was so many they were all over the roads.

Wooly worm

Saw one this fall..was almost all reddish with tad of dark on each end. Oakbrook il

Woolly Bear Caterpillars

In the past week,I have seen one that was nearly all brown and one that was nearly all black. Now what!

differing woolly worms

It sounds like those two caterpillars are having a difference of opinion over their predictions for upcoming winter! Actually though, folklore aside, scientists have found that the color is affected by several factors, including the age of the caterpillar and the environmental conditions of the past winter. For more information, you might be interested in this page:
http://www.almanac.com/content/woolly-bear-caterpillars-and-weather-pred...

Woolly Worm Wake Forest NC

I found a solid Black Woolly Worm today after work.

FredVegas, VA sighting

Saw 3 this past weekend -- 2 in So. MD (both totally black) and 1 in VA (mostly black, w/tinge of rust). We've been having increasingly harsher winters in NOVA the past 4-5 yrs. We'll see if these 3 prognosticators were close nuff for that cigar.

psychotic woolly bears

I'm in eastern PA. I've seen several with very wide rust bands and several that are completely black. They're the politicians of the caterpillar world, evidently.

Wooly Bears

I'm a bit frightened to say this, but I have seen several that are solid black!!

Wooly bears

Me too! That is what brought me to this article.

Woolly worm

My grandparents always told me that all colors mean something. For instance, if the front was black winter would start off bad, middle brown mild, last part black bad. Or the opposite if colors are reversed. With that being said, I have seen two so far one was all black and the other one was mostly brown in the middle. So I'm not sure.
French Creek, WV

wooly worms

Why havent I seen any wooly worms at all this fall?

Woolly Worms

I've seen two and they have been pure black with no brown at all. :(

All Black in SE PA

I saw one woolly bear about a month ago, back in September. It was short and solid black. Hoping that means lots of snow for skiing! My husband is a teacher so we love snow days!

Wooly Caterpillar

All rust, not a hint of black. From Eagleville, TN.

Woolly Catapillar

This weekend during our daily walk several displays of very small fuzzy woolly's were crawling on the street doing a rust color coat. No stripes, no black, just rust. This is in the Central Pennsylvania region near the capitol. Looks like a mild winter here!! (based on Almanac data)

Woolly Worm

Just came across a Woolly Worm with a wide brown band in Franklin, TN. He was so cute and fuzzy. Looking forward to learning more about them.

Wooly Bear sightings

My daughter just came over to me & told me she just saw an all black wooly bear in our backyard in Townsend, DE. Oh boy... can't wait to see if it's going to be a rough winter!! She is very excited!!!

Wooly worm

we just saw our first wooly on our back porch,we live on a farm in mid mo.and he was very fat and black as night from end to end,bet we have a heavy winter.Sept.10,2016

wooly bear caterpillar

The caterpillars here in Yelm have wide spaces between the black. Here's hoping for a mild winter.

Seeing a woolly worm

I saw my first woolly a couple days ago. It was all black. They are really cute little creatures. I enjoyed reading about them.

Found one in my laundry room

Found one in my laundry room scared the crap out of me!!!!! Scooped it in a cup as soon as I seen it. I didn't know if it would hurt my son who is a year and a half

Red and Black Wolly Worm Caterpillar

I first saw him in the back yard last week and again today, the first day of spring. We had a mild winter and it is looking for a place to make a cocoon, I think.

wooly bear caterillar

i got a wooly bear caterpillar in my jar now and it is all black what that mean

southern Wisconsin

Saw one yesterday at Horicon Marsh in southern Wisconsin with a large brown band in the middle. It was very determinedly heading west. Folklore in my home state of Missouri says that a woolly bear moving south means a rough winter. I have no idea what heading west might mean other than he knew he could find a rock in that direction.

Southern wisconsin here also.

Southern wisconsin here also. Same coloring as the one spotted near Horicon marsh. Wide rust band in the middle. Not sure which direction THIS one was headed, tho. He was curled in a defensive little ball. :)

Wooly Bear Worms

I saw one today he was all BLACK, so far my State has missed several years of bad weather. So the winter of 2015/2016 must be going to be severe. Time to stock up on supplies.

Woolley bear

Saw a woolly bear tonight around 7:30 pm on the floor of our horse barn. First one this year.Laying out flat it was all black and the bristles seemed extremely long from others I've seen. When it curled into a ball I could faintly see rust color in the middle of the body. We are about 30 miles SW of Lansing MI

Just found a woolly

Just found a woolly caterpillar. Its black bands were close together. There wasn't as much orange as usual. Black bands were wide. Kinda early to see them. Found this guy in the yard. NW michigan across from Green Bay.

1/7/15 Cumming GA We have

1/7/15 Cumming GA We have lived in the same home for 7 years and I have never seen one, ours is solid black. The weather has fluctuated and our new outdoor pet travels (very slowly) around sidewalk apx. 5 ft from the front door and the landscaping there. It has been enjoyable to see if and where he is as we go in and out!

3/4/14 I live in NW Indiana

3/4/14 I live in NW Indiana where spring has not begun yet. We had a snow storm Sunday, and near zero temperatures overnight. I saw a "Wooly" today on my patio!!! A sign of Spring, I hope!!

I saw a woolly bear today

I saw a woolly bear today 1/26/14. The center rust/brown band was at least 1/2 the length of the caterpillar with only very narrow black end bands. I sure hope that's predicting an early spring.

I just saw a Wooly Bear today

I just saw a Wooly Bear today on 1/14/2014 in Louisville, KY

JUST SAW A WOOLY BEAR TODAY

JUST SAW A WOOLY BEAR TODAY ON DECEMBER 4, 2013. THE RUST PART OF THE FUR IS ONE THIRD THE LENGTH OF THE CATEPILLAR.

I just took a photo of a

I just took a photo of a wooly bear in Morristown, NJ. Dec. 4, 2013. The rust band equals one third of the length of the catepillar.

..i just held one and put it

..i just held one and put it on a leafy bush..there's been a good amount of them around here..just discovered here what they were called.. i live in the hudson valley area in new york..most of them have been half and half with the rust and black..some more or less with one color or another..but i didn't know about the coloring meaning something..so i'll keep better track of what i find from now on..i find if you pick one up and it curls into a ball..blowing very very gently on it..makes it come out of the ball and start walking again..i always put them on a leafy bush..they like it and crawl inside the branches..

I live on the South Shore of

I live on the South Shore of Nova Scotia, and they seem to be out and about everywhere.

Got some nice photos yesterday, and the bands were wide, thus I expect a mild winter :) Yeah! Yay!

Will gladly share my photos, just not sure where :)

Wooly bear here in Central

Wooly bear here in Central Minnesota has a small rusty colored band around its middle.

I live in western central OH

I live in western central OH and I've seen many woolly bears and everyone of them are totally black.

I saw one a couple of weeks

I saw one a couple of weeks ago and it had a big brown band! I'm ready for another mild winter. I live in central Michigan.

Far north central Wisconsin,

Far north central Wisconsin, the only wooly bear I saw was all black. They have been rare up here in the last 5 years. Because of drought?

I live in PA and the wooly

I live in PA and the wooly bears have a small black band in front and back the middle is brown and larger than the black ....MILD winter? I always have faith in them. I am 72 years old so I know these wooly creatures a long time.

I live in Western West

I live in Western West Virginia and every wooly worm I've seen are completely black.

I'm from delmar on the

I'm from delmar on the eastern shore of maryland, and the most I have seen have been mostly rust with little black and white ones.

Here on Eastern Shore of

Here on Eastern Shore of Maryland we are loaded with them! For what it's worth, right now they are mostly rust colored. It's been quite warm, no frost yet.

I saw one a few weeks ago in

I saw one a few weeks ago in North Alabama and it was solid black.

I saw one a few weeks ago in

I saw one a few weeks ago in n.Alabama and it was all black.

I have seen a few Woolly

I have seen a few Woolly Bears in the last week or so here in the Shenandoah Valley. They all were just about black.

I did NOT see many wooly

I did NOT see many wooly worms this year....why? The one I did see showed me his orange band.....and he did not have a very black, thick coat...!

the only 1 ive seen so far

the only 1 ive seen so far this year was solid white

The first woolly bear I've

The first woolly bear I've seen so far in south east Kentucky had unequal black bands, the back was smaller.

I have not seen many woolly

I have not seen many woolly bears this year and saw only 8-9 butterflies all summer.
Dean

I saw a wooly bear a few days

I saw a wooly bear a few days ago and it had two black stripes and one rust stripe that seemed to be divided almost equally in thirds.

Moist turkey, crispy skin.

Holiday Dinner Plans
Prize winning Pilgrim Turkey recipe.

 

You will also be subscribed to our Almanac Companion Newsletter

solar_array.jpg

Solar Energy Production Today

0.00 kWh

Live data from the solar array at The Old Farmer's Almanac offices in Dublin, NH.