Can Animals Predict the Weather?

You may have heard some version of this before:

Cows lie down before rain.

Birds fly lower before a storm.

Dogs become restless before thunder.

Cats suddenly hide when bad weather is coming.

For centuries, people have watched animals for clues about the weather. And while animals are not tiny meteorologists with access to tomorrow’s forecast, there is some real science behind the idea that they can notice a storm before we do.

The explanation is probably much less mysterious than a “sixth sense.”

Animals simply experience the world differently.

Your Dog May Hear the Storm Before You Do

Dogs can hear sounds at higher frequencies and from greater distances than humans can. That means a dog may hear distant thunder long before you are aware that a storm is approaching.

This may explain one of the stranger experiences familiar to people with storm-anxious dogs: the sky still looks reasonably normal, but the dog suddenly starts pacing, hiding, or following you around.

Cartoon showing dog following it's owner

Twenty minutes later, you hear thunder.

The dog didn't necessarily predict anything. He may simply have received the weather report before you did.

The American Kennel Club notes that dogs' superior hearing can allow them to detect thunder well before humans hear it. (American Kennel Club)

They May Feel the Air Changing

Thunderstorms don't just bring rain and noise. They are accompanied by changes in the atmosphere.

One of those changes is barometric pressure.

Air pressure commonly falls as a storm approaches, and dogs appear capable of detecting those changes. Veterinary sources also suggest that dogs may respond to increasing static electricity and changes associated with lightning. (Vca)

For a sensitive dog, the approaching storm may therefore be producing several signals at once:

distant thunder we can't yet hear, changing air pressure, increasing wind, unusual smells, darkening skies, and electrical changes in the atmosphere.

Suddenly the supposedly psychic dog doesn't seem quite so psychic.

He's just working with better equipment.

Can Dogs Smell a Storm?

Possibly.

Dogs have an extraordinarily sensitive sense of smell, and veterinary sources suggest they may detect atmospheric changes associated with approaching storms, including changes in ozone. (Vca)

Humans sometimes notice that distinctive smell before or after a thunderstorm too—that fresh, sharp scent often associated with rain.

A dog's nose is operating on an entirely different level from ours.

So when your dog pauses at the door, lifts his nose into the air, and decides he'd rather not go for a walk, he may be detecting environmental changes you haven't noticed yet.

Or he may just not want to go for a walk.

Dogs remain dogs.

It Isn't Just Dogs

Some of the strongest evidence that animals respond to approaching weather actually comes from much smaller creatures.

Researchers have found that some insects change their behavior when atmospheric pressure changes.

In experiments involving beetles, moths, and aphids, falling barometric pressure—the kind often associated with approaching storms—changed mating behavior. Some insects reduced courtship activity, apparently avoiding the risks of being exposed during strong wind and rain. (Smithsonian Magazine)

From an evolutionary standpoint, that makes sense.

If you weigh a fraction of an ounce and spend your life flying around outdoors, knowing that bad weather is approaching could be extremely useful.

Sometimes the smart move is simply:

Stop what you're doing and find shelter.

What About Birds?

Bird behavior has probably inspired more weather folklore than almost any other animal.

“Birds fly low before a storm” is one familiar example.

There are plausible reasons why weather affects where and how birds fly. Atmospheric pressure, wind, turbulence, temperature, and the behavior of the insects they eat can all influence flight.

Researchers have even used sensors carried by birds to study atmospheric turbulence, demonstrating just how closely flying animals interact with small changes in the air around them. (ScienceDaily)

But that is different from saying that a flock of birds can reliably tell us whether it will rain tomorrow at 2 p.m.

Animals are responding to conditions already developing around them.

They aren't forecasting in the way meteorologists do.

And Then There Are the Cows

The belief that cows lie down when rain is coming is wonderfully persistent.

The usual explanation is that cows somehow sense approaching rain and sit down to preserve a dry patch of grass underneath themselves.

It's a charming story.

It's also not a very dependable weather forecast.

Cows lie down for lots of reasons, including resting and ruminating. A field full of reclining cows tells you considerably more about what the cows feel like doing than what tomorrow's weather will be.

That illustrates an important problem with animal-weather folklore.

We tend to remember the time the cows lay down and then it rained.

We don't remember all the afternoons when the cows lay down and absolutely nothing happened.

Cartoon of two cows sitting near a family leaving their picnic

What About Earthquakes?

This is where the story becomes even more interesting—and much more controversial.

Reports of animals behaving strangely before earthquakes go back thousands of years. The U.S. Geological Survey notes an account from 373 BC, when rats, snakes, weasels, and centipedes were reportedly seen leaving an area before a destructive earthquake in Greece. (USGS)

Stories like these continue today.

Dogs bark inexplicably. Birds leave. Fish behave strangely. Livestock become agitated.

But scientists have not found a reliable pattern that allows animal behavior to predict earthquakes. USGS says there is no reproducible connection between a particular animal behavior and an impending earthquake. (USGS)

There is one thing animals genuinely can do.

Earthquakes produce a weaker, faster-moving P-wave before the stronger shaking arrives. Some animals are sensitive enough to notice that first wave seconds before humans notice the earthquake.