Can an insect and a cup of coffee predict the weather?

A pair of interesting weather folklore examples
Published: Oct. 14, 2021 at 11:21 AM CDT
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MONTGOMERY, Ala. (WSFA) - It may come across as a very strange question, but is it possible that an insect or a cup of coffee can predict the weather? The insect we’re referring to is the woolly bear caterpillar, and the cup of coffee we’re talking about is that morning cup of joe.

Yeah, we know, how in the world can we seriously be talking about a caterpillar and a cup of coffee predicting what Mother Nature will do?

That is an entirely fair question.

Each of these falls in the weather folklore department. The woolly caterpillar and cup of coffee are just two of many different weather folklore examples that have been handed down from generation to generation.

Let’s start with the woolly caterpillar, which you can read more about by clicking here. It’s said that the length of the brown and black stripes on a woolly caterpillar is linked with the severity of the upcoming winter season.

Can a woollybear caterpillar predict the winter? Not so much.
Can a woollybear caterpillar predict the winter? Not so much.(WSFA 12 News)

The longer the woolly bear’s black bands, the more severe the winter will be. The severity of a winter season refers to how long, cold and snowy it is. So long black bands equate to long, cold and snowy winters in the area where they are spotted.

On the flip side, the wider the middle brown band is, the milder and more tranquil the upcoming winter will be.

Sound believable? There are people who swear by this and other weather folklore. However, -- and it’s unfortunate -- there is no scientific correlation between a woolly bear caterpillar’s stripe length and the upcoming winter season.

That morning cup of coffee, though...what’s up with that?

It’s said that if you pour yourself a hot cup of coffee in the morning you can tell what the day will be like.

Can a cup of coffee predict the day's weather? Not so much.
Can a cup of coffee predict the day's weather? Not so much.(WSFA 12 News)

If the bubbles collect near the center of your cup of coffee then high pressure is in control. That means tranquil and quiet weather. Similarly, if the bubbles collect along the rim of the cup you have low pressure in place. Low pressure means unsettled weather -- usually includes precipitation of some sort.

The problem with this experiment is you need the following:

  • Perfectly round mug or cup
  • The temperature of your coffee has to be just right
  • There has to be a detectable pressure change over your house

There hasn’t been a whole lot of scientific testing done when it comes to this particular example of weather folklore. The best way to determine whether or not it works is to try it for yourself! If you notice no bubbles, try adding creamer or a spoonful of additional coffee.

What do you see? Send an email to and let me know! I’m going to lean towards this not being truly trustworthy folklore based on the amount of variables involved that could be juuuuuust off.

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