Weather forecasting was one of the first sciences tackled by early cultures, and it's easy to see why. Everything from vital crops to conquering armies succeeded or failed on the whims of the weather. Ages passed before atmospheric augury moved from the province of prophecy to the scientific sphere, but farmers, sailors and soldiers were not content to wait. Thus, lacking sophisticated instruments, coordinated observatories or rapid communications, they based their forecasts on inherited idioms and timeworn lore.
In the West, these early rules of thumb gave way first to natural philosophy, exemplified by Aristotle's rigorous but flawed Earth studies compendium "Meteorologica." Much later, scientific theories born of compiled observations would establish modern meteorology.
In the meantime, superstitions continued to guide human enterprises, sometimes in surprising ways. According to some historians and geographers, the erroneous claim that "rain follows the plow" -- that is, that cultivated land attracts more precipitation -- supported, and perhaps helped drive, the westward expansion of America [source: Ferrill].
Confirmed, busted or plausible, weather myths die hard, so we've compiled a list of 10 that we're confident hold water. Some are as warm and familiar as a summer wind, while others, we hope, are as shocking as a bolt from the blue.
Red Sky in Morning, Sailors Take Warning; Red Sky at Night, Sailors Delight
The ruddy shades that tint the horizon at break and close of day result from the scattering of sunlight by small particles suspended in dry, dusty air. At sunset, these conditions imply a zone of dry, high pressure between you and the sun. Since weather in the mid-latitudes moves mainly west to east, that means a day of clear sailing. But in the atmosphere, as in life, highs and lows tend to follow hard upon one another. So, if the red, dusty skies occur near sunrise, it suggests that the calm high-pressure zone has already passed and that a stormy low-pressure system could move through soon [source: Library of Congress].
The saying works fairly well in the middle latitudes, which include most of North America, Europe, and Asia, as well as South Africa and the southern halves of South America and Australia. At the poles and in the tropics, where weather tends to progress in the opposite direction, sailors (and shepherds) would do well to take the opposite advice [source: Pann].
Feeling Bad Weather in Your Bones
The idea of feeling "under the weather" is as old as Hippocrates, one of the fathers of Western medicine, who recorded that certain illnesses seemed to worsen under particular meteorological conditions. Today, people still claim they can feel the approach of a storm or a cold snap in their arthritis, sinuses, headaches or teeth. But does grandma's "rheumatiz" acting up make for a good barometer, or is this just another case of anecdotal evidence run amok?
Modern scientists have found no conclusive evidence for a broad correlation between pain and weather, but studies have shown statistically significant links in a few specific cases [source: Shah]. For example, a 2007 American Journal of Medicine study of 200 subjects with knee osteoarthritis found a link between barometric pressure and pain level [source: McAlindon et al.].
Barometric pressure turning rain into pain makes intuitive sense. Your bodily fluids exist in a constant balance with ambient air pressure, so as the barometer falls -- as happens with an approaching storm -- your tissues can swell in response, irritating nerve endings and causing you additional ouches [source: Shah].
Using Crickets as Thermometers
The wing-sawing repertoire of crickets runs deep and comprises tunes suited to every occasion, from attracting mates to announcing danger [source: Library of Congress]. But did you know that their chirping also bears a direct relation to air temperature?
Crickets chirp faster in warmer conditions and more slowly as the air turns more frigid. In some species, such as Oecanthus fultoni, aka the "thermometer cricket," chirp rate and temperature share a strikingly direct and linear relationship (within a specific temperature range from 18 to 32 C, or 64 to 90 F). In other species, the connection is less pronounced, but the rule generally works [source: Doherty].
Indeed, research has shown that you can calculate air temperature by counting nearby cricket clicks and entering them into a simple formula. In an 1897 edition of The American Naturalist, A. E. Dolbear derived the formula as T = (50 + N – 40) / 4, where T = temperature (F) and N = chirp rate per minute [source: Dolbear]. "The Farmer's Almanac" says to count the number of chirps occurring in 14 seconds, and then add 40 to get temperature in Fahrenheit. For Celsius, it says to count number of chirps in 25 seconds, divide by 3, and then add 4 [source: Farmer's Almanac].
So the next time crickets keep you awake, don't count sheep -- calculate air temperature.
Cows Lying Down Means Wet Weather Is on the Way
Animal behavior has long been a favorite weather indicator, and a whole herd of superstitions crowd around cows. It's said, for example, that a cow fed its own hairs will forget its previous home, or that a cow with a piece of its tail lopped off will never run away [source: Farmer's Almanac].
Cows have a long history as weather predictors, too. One superstition claims that a cow lies down when rain is coming. Given that cows lie down for a variety of reasons, including cud chewing, it's tempting to dismiss this claim as "udderly" ridiculous, but further rumination suggests that it might have a leg to stand on after all. The reason? A possible, albeit tenuous, link between crouching cows and wet weather: body heat.
It turns out that cows tend to stand more often when their bodies overheat, so an upright Guernsey could arguably mean hotter weather while a seated shorthorn implies cooling weather or a storm a' brewin'. Still, we wouldn't bet the farm on it, as this maxim is likely a case of over-milking a coincidence [sources: Allen et al.; Farmer's Almanac].
A Lunar Halo Means Rain
In the proud custom that wise words stick better in the mind when they rhyme, you may have heard this one stated as "ring around the moon, rain real soon" or "when a halo rings the moon or sun, rain's approaching on the run."
Both maxims have the ring of truth about them. The halos that sometimes frame the moon or the sun are produced by high, wispy clouds made of ice crystals. These sky sparklers refract the sunlight or moonlight to create a kind of luminous halo. During the day, their light-bending properties can at times also produce bright splotches, called parhelia or "sun dogs," that look like false suns [source: UIUC].
These ice crystals typically occur in translucent, sky-spanning cirrostratus clouds, which form during large-scale convergence. In a common convergence scenario, a low-level, low-pressure zone forms, pulling in air from its environs. As converging air rises, it cools and forms water vapor. If it continues to rise into the higher, colder reaches of the sky, it will solidify into ice crystals [source: UIUC].
Cirrus clouds often move in ahead of weather fronts, where temperature differentials force warm air upward, condensing moisture and forming clouds. Thus the rainy reputation [source: Pidwirny].
Clear Moon, Frost Soon
As anyone who lives in the north-central U.S. can tell you, clear days in winter provide a mixed blessing. On the one hand, you enjoy a respite from the long march of dim, dreary days, when you find yourself wondering if that Norse myth about a wolf eating the sun might have something to it after all. On the other hand, clear days -- and clear nights -- often mean cold weather, brought to you by a dry, continental high-pressure zone. These systems tend to have words like "cold," "frigid" or "arctic" prepended to them because, as far as Earth's surface and lower atmosphere are concerned, a cloudless night is like a cold night without blankets.
During the day, the sun's shortwave radiation is absorbed by Earth and converted into heat. When the sun sets, the planet begins radiating this heat at various rates depending upon the materials involved. Lacking clouds to capture that heat and hold it in, the surface and atmosphere grow increasingly colder through radiative heat loss.
So there you have it. "Cold is the night when the stars shine bright," and frost warnings often coincide with clear nights.
March Comes in Like a Lion and Goes Out Like a Lamb
Whether you find this saying true (but pointless), merely a myth, or both, depends on your viewpoint about its origins.
In the Northern Hemisphere, March marks the shift from winter to spring, so by definition one would expect that conditions would begin cold and stormy and transition to mellower, warmer weather by month's end. If that doesn't strike you as especially helpful, you can look to the night sky for another explanation offered by the proverb's proponents: March kicks off with the constellation Leo (the Lion) on the eastern horizon at sunset but comes to a close with Aries (the Ram) on the western horizon. By their lights, it's a star thing.
Both reasons make the saying technically true but useless, which may explain why some versions add a few key words: "If March Comes in Like a Lion, It Will Go Out Like a Lamb." In keeping with the usual pattern of weather superstitions, this maxim makes a prediction: Rough weather during the first of the month means pleasant conditions at its close.
Whatever the proper version, we must sheepishly point out that there's no correlation between inclement weather at the beginning of March and pleasant weather later [source: Hambling]. But please don't bite off our heads about it.
Pine Cones Can Predict the Weather
There are two main types of superstitions tying plants and animals to weather forecasting: Those that imply that the flora and fauna "know" what the coming season (typically winter), will bring, and those that rely on the physics, chemistry and biology of living things responding to changing conditions. The former generally don't hold up -- plants and animals react to their past or present environments, they don't predict the future -- but there's definitely hope for the latter.
For example, some say that a profusion of pine cones in fall means a cold winter to follow. This one's a bust: Actually, pine trees can take three years to fully grow cones, and varying their cone production from year to year helps them throw off predators [source: WBZ]. However, you can use pine cones to predict weather in another way: watching as they open or close.
Pine cones are the procreative parts of pine trees. Male versions produce pollen, and pollenated female forms yield seeds. Under dry conditions, the outer parts of the cones' scales dry more than the inner parts, causing the cone to open. This is good news for the tree, since dry, calm weather provide a better environment for seed dispersal. In wet weather, the scales absorb moisture and swell shut, shielding the seeds until better days roll around [source: Burns].
Mackerel Sky and Mare's Tails Make Lofty Ships Carry Low Sails
Here's a fish story that actually holds up -- as long as you keep a tight rein on the details.
A mackerel sky, known in Germany and France as sheep clouds (German: schaefchenwolken; French: nuages moutonneux), is a large, spreading assemblage of clouds that resembles a series of waves or fish scales, with blue sky peeking out between the puffs. It consists of cirrocumulus or altocumulus clouds, which indicate moisture high up (around 18,000-30,000 feet (6,000-10,000 meters) in a cold sky (the blue bits indicate that these clouds are breaking up due to instability in the air). Mare's tails, meanwhile, are long, threadlike cirrus clouds, often stretched by strong high-level winds. Both clues suggest an impending storm, typically 6-8 hours away [source: Weather Online].
That is, assuming your mackerel sky is caused by ice clouds. It's also possible, if the clouds mostly consist of bigger, darker altocumulus, that you're dealing with a lower-level, water-droplet-based version. This could mean better weather in the short run, but keep a weather eye on that sky: If they continue to develop, a cold front and thunderstorms might soon be on the way [source: Weather Online].
Counting Lightning Flashes and Thunderclaps Can Tell You a Storm's Distance
In compiling this list, we looked at several false beliefs about thunder and lightning. For example, the notion that lightning never strikes twice is doubly wrong. First, about a third of the time, individual lightning bolts strike more than once at a single go [source: NASA]. Second, the same spots -- skyscrapers, for example -- can and do receive multiple strikes per year. So do some people: Ranger Roy Sullivan of Shenandoah National Park, for example, was struck by lightning on seven separate occasions [source: Dunkel]. Ouch.
But the counting rule can be counted on, because it's based on physics: Light travels a lot faster than sound, and the speed of sound in the atmosphere is a known quantity. According to the lore, after seeing a lightning flash, you should count the number of seconds that pass before you hear the thunder. Every five seconds equates to a mile of distance between you and the storm. The math makes sense: At sea level and around 68 F (20 C), sound travels through the atmosphere at around 1,129 feet per second (344 meters per second). Thus, for every five seconds between lightning and thunder, the sound travels 5,645 feet (1,720 meters), or roughly a mile and some change [source: NOAA]. If nothing else, you can use the trick to figure out if the storm is moving toward you or away.
Santa Ana winds blow during California's dangerous dry season. HowStuffWorks explains how they whip up wildfires that can ravage thousands of acres.
Author's Note: 10 Scientifically Sound Weather Superstitions
As someone with two degrees in climatology/meteorology, I've heard more than my share of anecdotal weather wisdom. This article gave me a welcome chance to finally research several classics (debunking most of them) and to discover a few new ones in the process.
Of course, weather is very complex. There's a reason weather predictions suffer accuracy hits beyond a few days, and that chaos theorists use weather as a paradigm case. Even the rules-of-thumb listed here only work a percentage of the time. Still, you might find a few of them useful in a survival situation, or out at sea, or as a fun science project to try with your kids.
- Allen, J. D. et al. "Managing Heat Stress and Its Impact on Cow Behavior." Western Dairy Management Conference. March 6-8 Reno, Nevada. (Dec. 11, 2014) http://www.wdmc.org/2013/Managing%20Heat%20Stress%20and%20Its%20Impact%20on%20Cow%20Behavior.pdf
- Burns, Katie. "Q & A -- Why Do Pine Cones Open and Close?" San Diego Union-Tribune. Feb. 11, 2001. (Dec. 11, 2014) http://www.utsandiego.com/news/2001/feb/11/q-a-why-do-pine-cones-open-and-close/
- Doherty, John A. "Temperature Coupling and 'Trade-Off' Phenomena in the Acoustic Communication System of the Cricket, Gryllus Bimaculatus De Geer (Gryllidae)." The Journal of Experimental Biology. Vol. 114. Page 17. 1985. (Dec. 9, 2014) http://jeb.biologists.org/content/114/1/17.full.pdf
- Dolbear, A. E. "The Cricket as a Thermometer." The American Naturalist. Vol. 31, no. 371. Page 970. November 1897. (Dec. 9, 2014) http://www.jstor.org/stable/pdfplus/2453256.pdf
- Dunkel, Tom. "Lightning Strikes: A Man Hit Seven Times." The Washington Post. Aug. 15, 2013. (Dec. 12, 2014) http://www.washingtonpost.com/lifestyle/magazine/inside-the-life-of-the-man-known-as-the-spark-ranger/2013/08/15/947cf2d8-ea40-11e2-8f22-de4bd2a2bd39_story.html
- The Farmer's Almanac. "Cricket Chirps: Nature's Thermometer." (Dec. 9, 2014) http://www.almanac.com/cricket-chirps-temperature-thermometer
- The Farmer's Almanac. "Is It True That Cows Lie Down When It's About to Rain?" Jan. 1, 2006. (Dec. 10, 2014) http://farmersalmanac.com/weather/2006/01/01/is-it-true-that-cows-lie-down-when-its-about-to-rain/
- Hambling, David. "Weatherwatch: Spring Comes in Like a Lion, Goes Out Like a Lamb." The Guardian (UK). March 9, 2012. (Dec. 11, 2014) http://www.theguardian.com/news/2012/mar/09/weatherwatch-spring-storms-constellations
- The Library of Congress. "Can You Tell The Temperature by Listening to the Chirping of a Cricket?" Aug. 9, 2011. (Dec. 9, 2014) http://www.loc.gov/rr/scitech/mysteries/cricket.html
- The Library of Congress. "Is the Old Adage 'Red Sky at Night, Sailor's Delight. Red Sky in Morning, Sailor's Warning" True, or is It Just an Old Wives' Tale?'" Oct. 2, 2014. (Dec. 16, 2014) http://www.loc.gov/rr/scitech/mysteries/weather-sailor.html
- McAlindon, Tim, et al. "Changes in Barometric Pressure and Ambient Temperature Influence Osteoarthritis Pain." The American Journal of Medicine. Vol. 120, no. 5. Page 429. May 2007. (Dec. 9, 2014) http://www.sciencedirect.com/science/article/pii/S0002934306010266
- NASA. "Lightning Really Does Strike More Than Twice." Jan. 14, 2003. (Dec. 12, 2014) http://www.nasa.gov/centers/goddard/news/topstory/2003/0107lightning.html
- National Oceanic and Atmospheric Administration (NOAA). "Distance to Lightning." (Dec. 12, 2014) http://www.nws.noaa.gov/om/educ/activit/lightng.htm
- Pidwirny, M. "Air Masses and Frontal Transitional Zones". In Fundamentals of Physical Geography, 2nd Edition. 2006. (Dec. 16, 2014) http://www.physicalgeography.net/fundamentals/7r.html
- Shah, Allie. "Is Weather a Barometer of Painful Joints and Achy Bones?" Star Tribune. Dec. 9, 2014. (Dec. 9, 2014) http://www.startribune.com/lifestyle/health/285128431.html
- University of Illinois at Urbana-Champaign. "Cirrostratus Clouds." (Dec. 16, 2014) http://ww2010.atmos.uiuc.edu/%28Gl%29/guides/mtr/cld/hgh/crss.rxml
- University of Illinois at Urbana-Champaign. "Sundogs." (Dec. 16, 2014) http://ww2010.atmos.uiuc.edu/%28Gh%29/guides/mtr/opt/ice/sd.rxml
- WBZ. "Curious Why There Are So Many Pine Cones." Oct. 1, 2010. (Dec. 11, 2014) http://boston.cbslocal.com/2010/10/01/curious-why-there-are-so-many-pine-cones/