General Signs
Usually, you can predict the next 24 hours’ weather without instruments by observing key details that show:
- Air pressure changes
- Humidity changes
- Cloud movement
- The moon’s appearance
Most animals react to changes in air pressure and humidity.
In most regions, weather fronts move in the same east-west or west-east direction, meaning that you can usually see the next half-day on the horizon.
- If you don’t know for sure, the sun’s heat subtly affects weather enough to where most of the world’s weather runs east-west.
If you’ve had an injury or infirmity, you might feel changes in air pressure.
Generally, high-pressure fronts have pleasant weather and low-pressure has worse from the high-pressure air moving in to achieve equilibrium.
Signs that show the weather will get worse
In the sky
Turbulent winds are pulling the clouds if they’re going different directions.
Cumulonimbus clouds (rain clouds) often show up early in the day and develop throughout the day.
You can typically see cumulus towers (very tall rain clouds) before rain.
Cirrus clouds (wispy hair-like clouds) or altocumulus clouds (chunks of clouds like mackerel scales) show high winds at high altitudes.
- High winds can lead to inclement weather within 36 hours.
A ring around the moon means probable rain within three days.
- The ring comes from reflected light off clouds connected to warm fronts and moisture.
The moon is bright and sharply focused before rain.
- Low-pressure air has cleared out any dust to obscure it.
In the environment
Animals behave differently before a storm:
- Animals, especially birds, become quiet before rain.
- Cattle huddle closer together and cows lie down.
- Ants build their hills with very steep sides just before a rain.
- Cats tend to clean behind their ears before rain.
- Turtles often search for higher ground one or two days before heavy rain.
The air will smell like compost and swamps will smell horrible.
- Plants release their waste in a low-pressure environment.
- Gases naturally release from lower air pressure.
Strong winds can indicate a rapid change in weather.
Smoke from fire will swirl and descend from the low air pressure.
Humidity will increase:
- Hair curls up and gets frizzy.
- Oak and maple leaves curl.
- Wood swells and can affect door frames.
- Salt clumps together.
- Odors of all varieties are stronger in moist air.
- Pine cone scales close in high humidity and open in dry air.
Lightning calculation:
- Count the number of seconds between a lightning flash and the thunder.
- Divide that number by 5 for the distance in miles, and by 3 for the distance in kilometers.
Signs that show improving weather
Sinking air from a dissipating storm cloud create mammatus clouds (thick bumpy clouds like an inverted carpet).
Cloud cover on a winter night means warmer weather is coming since it keeps heat from escaping.
Usually, the sun rising will dissipate some cloud cover.
Signs you can read both ways
It will rain a long time if birds are eating in a storm, but if they don’t, it will clear up soon.
Look at whether smoke rises or curls.
- Lower-pressure fronts drive smoke downwards.
The grass at sunrise will be wet in good weather and dry in bad weather.
- Dry grass typically means clouds or strong breezes.
Watch if coffee bubbles move to the edge or stay in the center.
- Bubbles naturally float to the edge, but lower-pressure air pushes them to the center.
Watch how high birds fly or if they’re sitting on power lines.
- The higher pressure at high altitudes in low-pressure fronts hurts birds’ sensitive ears, so they fly close to the ground.
- Conversely, they fly higher in better weather.
If you see a rainbow, observe when you see it.
- A rainbow shows moisture where the evening usually shows the weather improving and morning getting worse.
Observe when the sky is red.
- The red sky is a high-pressure front stirring dust in dry air.
- Remember the mantra: red sky at night, sailor’s delight, red sky at morning, sailors take warning.
- Sometimes you can observe it with a red tint or paleness from the moon.