Weather signs without instruments: what holds up and what does not
"Red sky at night, shepherd's delight": some old weather rules have a grain of truth, others are pure superstition. Here you learn the signs that really pay off on a trip – sky colour, a ring around the sun and moon, contrails, morning dew, a turning wind, towering clouds and thunder – and why animals are not reliable weather prophets. No sign replaces the forecast, but on the way they help you turn back in time.
- Observe as you go, a few minutes per look
Explained simply
In the past there was no weather app. So people watched the sky and invented rules such as "red sky at night, shepherd's delight".
Some rules are often right: a large ring around the sun or moon can announce rain, and clouds growing tall at midday can bring thunderstorms.
Others are not: cows, frogs or aching knees do not predict the weather. The safest thing is always the weather forecast.
How it works
Here the weather usually comes from the west. If the western sky is clear in the evening, the setting sun glows red – and clear weather is on its way.
Moisture high up shows as veil clouds of ice that form a ring around the sun or moon, or as contrails that stay for a long time. They often come ahead of an area of rain.
Warm, moist air rises on summer days and forms heap clouds. If they grow tall already in the morning, they have the strength for thunderstorms by afternoon.
What matters
Look at several signs together, not just one.
Look in all directions, especially to the west.
Watch for changes: are the clouds thickening, is the wind turning, is the air pressure falling?
Safety: what to watch out for
Read the forecast and warnings before every trip.
With towering clouds in the morning in the mountains, turn back early.
If you hear thunder, get away from summits, ridges, single trees and water at once.
Step by step
Sky colour in the morning and evening
Red sky in the west in the evening often shows clear air where the weather comes from – rather good weather. Red sky in the morning with an already cloudy western sky can mean moisture is moving in. The rule is right more often than wrong, but not certain.
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Sky colour in the morning and evening
Red sky in the west in the evening often shows clear air where the weather comes from – rather good weather. Red sky in the morning with an already cloudy western sky can mean moisture is moving in. The rule is right more often than wrong, but not certain.
- 2
Ring around the sun or moon
A large bright ring around the sun or moon forms in thin veil clouds of ice. They often come ahead of a warm front: rain can follow in 12 to 24 hours.
- 3
Contrails
If contrails disappear quickly, the air up high is dry. If they stay for a long time and spread out, it is moist – often an early sign of a change in the weather.
- 4
Dew and wind in the morning
Lots of dew or frost after a clear, calm night usually means a dry day. If the wind turns and strengthens while clouds thicken, worse weather often follows.
- 5
Towering clouds at midday
If heap clouds grow tall already in the morning and turn dark or fibrous at the top, thunderstorms threaten in the afternoon. This is the most important sign in the mountains: descend in time.
- 6
Count lightning and thunder
Count the seconds between lightning and thunder and divide by three: that is the distance in kilometres. If you can hear thunder at all, you are already in danger.
Thunder audible: seek shelter at once.
Common mistakes
- Using weather signs instead of the forecast
- Treating animals as weather prophets
- Ignoring towering clouds at midday
- Carrying on while thunder is audible
- Looking in only one direction
Quick view
Materials
Altimeter (barometric)
Shows pressure changes when you stay in one place
Shows wrong altitudes when the weather changes – recalibrate regularly at known spot heights.
Suitable for
- Hikes and mountain tours
- Camping outdoors
- Areas without signal
Not suitable for
- A substitute for weather warnings
- Forecasts for several days
Prerequisites
- Forecast read before the trip
- Looking at the sky regularly
- Turnaround time fixed
How it works
In Central Europe weather usually comes from the west. What you see in the west often comes to you; what lies in the east has often already passed. Many signs show moisture high in the air – such as ice crystals forming a ring around the sun or moon, or contrails that stay. Such moisture often comes ahead of a warm front that brings rain hours later.
Advantages
- Works without signal
- Trains the eye for changes
Disadvantages
- Only hints, no certainty
- Reliability varies by region
Deep knowledge
Background
Weather lore grew out of centuries of observation, when there were no weather services. Meteorologists have tested many of these rules: rules about sky colour, halos and dew often have a physical core, rules about particular calendar days or animal behaviour mostly do not.
In the Alps the old climbers' rule applies: if you want to be on the summit when the towering clouds grow, you set off too late.
Variants
- Animals and plants
- Low-flying swallows hunt insects that fly lower in moist air – a weak sign. Cows lying down, croaking frogs or aching knees are not reliable weather signs.
- Air pressure with the altimeter
- If you stay in one place and your altimeter suddenly shows more height, the air pressure is falling – often a sign of worse weather. If the pressure rises, it usually improves.
Common mistakes
- Using weather signs instead of the forecast
- Treating animals as weather prophets
- Ignoring towering clouds at midday
- Carrying on while thunder is audible
- Looking in only one direction
Limits and risks
- Applies to mid-latitudes with westerly weather
- No severe weather warning
Sources (3)
- Deutscher Wetterdienst (DWD): Wetter- und Klimalexikon · Halo, contrails, red sky and fronts explained
- World Meteorological Organization (WMO): International Cloud Atlas · Cloud types and their meaning for the weather
- NOAA National Weather Service (USA): Lightning Safety · Audible thunder means danger; wait 30 minutes after the last thunder