The Facts Behind Weather Folklore

Weather proverbs—the delightful, often rhyming, couplets and colorful statements that typically link a natural event with a meteorological condition—originated centuries ago when people watched the skies, oceans, plants, and animals for clues of what to expect weatherwise. Here’s why we, too, can rely on these age-old adages.

A Year of Snow, Crops Will Grow.

The Facts: A several-inch layer of snow contains more air than ice. Trapped between the interlocking snowflakes, the air insulates the plants beneath it. When the snow melts, the water helps keep the ground moist.

If There Is Thunder in Winter, It Will Snow Seven Days Later.

The Facts: According to Topper Shutt, chief meteorologist for WUSA-TV in Washington, D.C., this is true about 70 percent of the time, especially from the East Coast to the Plains. Thunder in winter is an anomaly often caused by a big dip and a big rise in the jet stream (a powerful wind current that acts like railroad tracks, guiding high- and low-pressure systems from west to east across North America and separating cold air in the north from warm air in the south). As cold air moves south, it replaces warm air and lifts it up, often causing thunderstorms. The cold air behind the front settles in. Depending on the strength of the front, it may hang around for many days. When the next weather system arrives several—if not exactly 7—days later, temperatures may still be cold enough to cause the moisture in the system to fall as snow.

A Ring Around the Moon Means Rain Will Come Real Soon.

The Facts: A ring, or halo, around the Moon is caused when the light of the Moon refracts through ice crystals present in high-level clouds. Although these clouds do not produce precipitation, they often occur in advance of an approaching low-pressure system, which often brings precipitation in the form of rain or snow.

Weather Clues

Weather clues are all around us. There are no real surprises, says Environment Canada’s David Phillips. Before a tornado, for example, the sky may turn green and the approaching wind might sound like a train at a distance.

Here are a few clues to making your own predictions:

Pay Attention to Winds and Clouds

These are the big predictors of changes in barometric pressure and resulting weather. For instance, the adage “No weather is ill, if the wind be still” indicates a high-pressure system, a broad area of descending air characterized by calm winds and little cloud formation.

Observe Sheep, Cats, and Cows

Their bodies are affected by changes in air pressure. When rain is on the way, old sheep turn their backs to the wind, cats sneeze, and cows lie down. Can animals predict the weather?

Watch Birds in Flight

Air pressure affects many birds. For example, swallows have sensitive ears; when the barometric pressure drops, they fly as close to the ground as possible, where air density is greatest. Low-flying birds are generally signs of rain, while high-flyers indicate fair weather. Learn more about how birds give weather forecasts.