Fact-check

Weather lore vs science

Twenty old sayings, one truth verdict each: TRUE, PARTIAL, or FALSE. Some of these are surprisingly accurate. Some are pure invention.

"Red sky at night, sailor's delight. Red sky in morning, sailors take warning."
True

At mid-latitudes, weather typically moves west to east. A red sunset means dry air is coming from the west (fair weather ahead). A red sunrise means the fair weather has already passed and moist storm-bearing air is arriving. This holds up scientifically in the Northern Hemisphere mid-latitudes.

"When clouds appear like towers, the Earth is refreshed by frequent showers."
True

"Towers" is a folk term for cumulonimbus development. Vertically growing clouds mean instability and rising air, both of which favor thunderstorms and showers. Perfectly accurate.

"Rain before seven, fine by eleven."
Partial

Weather systems in the UK often move fast enough that an early-morning shower has passed by mid-morning. In many maritime climates this is roughly right. In tropical or monsoonal climates, it's not.

"A ring around the moon means rain."
True

Halos around the moon (or sun) are caused by ice crystals in high cirrostratus clouds. Cirrostratus often precedes an approaching warm front, which brings rain within 12-36 hours. Legitimate short-range indicator.

"Cows lie down when rain is coming."
False

Studies of cow behavior have found no consistent correlation with precipitation. Cows lie down for many reasons, most of them unrelated to weather. If you see cows lying, you cannot conclude anything about rain.

"If the groundhog sees his shadow on February 2, six more weeks of winter."
False

Groundhog Day predictions match actual weather patterns no better than random chance. Punxsutawney Phil has been "right" about 39% of the time over a century.

"Mackerel sky, mackerel sky, never long wet, never long dry."
True

Mackerel sky refers to cirrocumulus patterns, which typically appear in changeable weather patterns. The saying accurately describes unsettled short-cycle weather.

"Rain follows the plow."
False

19th-century belief used to promote homesteading of the Great Plains — the idea that farming would somehow bring rainfall. Disastrously wrong. The Plains reverted to their natural drought cycles.

"Thunder in winter means snow in seven days."
Partial

Thundersnow is unusual and usually associated with strong cold-air outbreaks. Snow within a week is often correct in higher latitudes, but the seven-day specificity is folklore.

"When leaves show their undersides, expect rain."
True (mostly)

Increasing humidity makes leaves soften and orient differently. Strengthening pre-storm winds can flip leaves upward. Both point to weather changes, so this old saying has real basis.

"You can predict temperature from cricket chirps."
True

Dolbear's Law: count the chirps of a snowy tree cricket in 14 seconds and add 40 to get Fahrenheit. Amazingly accurate to within a couple of degrees. Different cricket species need different formulas.

"A rainbow in the morning is the shepherd's warning."
True

Same logic as red sky at morning. A morning rainbow means the sun is in the east and the rain-producing cloud is in the west — heading toward you.

"When the dew is on the grass, no rain will come to pass."
Partially true

Heavy dew forms on calm, clear nights with high humidity. Those conditions are typically not conducive to rainy weather in the next 12 hours. Reasonable short-term indicator.

"A cold winter means a bumper crop."
Partial

Cold winters do kill some crop pests. But cold winters can also damage roots and delay planting. Net effect on yield is minor at best.

"If March comes in like a lion, it will go out like a lamb."
False

No statistical relationship between early-March and late-March weather. Sounds nice, means nothing.

"Woolly bear caterpillars predict the winter."
False

Their color bands are related to their diet and life stage, not winter's severity. Charming legend, no science.

"When the wind is in the east, 'tis good for neither man nor beast."
Partial (in UK/Ireland)

In the British Isles, easterlies bring cold dry air from the continent (uncomfortable in winter) or hot dry air (uncomfortable in summer). Not universal — in New England, easterlies from the Atlantic can be very pleasant.

"Full moon brings storms."
False

Any correlation between moon phase and storms is not statistically significant. Studies find no relationship.

"When bees stay in the hive, rain is on the way."
Partial-True

Bees are sensitive to humidity, barometric pressure and temperature. Rapid changes in these preceding a storm do reduce their foraging. So bees "predicting" rain is real animal behavior, if inconsistent as a forecast.

"If ants are working, it will rain."
False

Ants work all the time. Rain has no consistent effect on ant activity that would make them a useful indicator.

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