“Red sky at night, hiker’s delight.
Red sky in the morning, hiker’s warning.”
Most people are familiar with the nautical version of this little bit of weather lore, but have you ever heard of these nuggets?
“When the dew is on the grass,
Rain will never come to pass.
When grass is dry at morning light,
Look for rain before the night.”
“If a circle forms ‘round the moon,
‘Twill rain soon.”
“When sound travels far and wide,
A stormy day will betide.”
They’re fun, old sayings that relate to weather, but do any of them actually hold water? Surprisingly enough, many do!
Red skies at night are an indication of light scattering through a high concentration of dust particles. This means a high pressure system with stable air flowing in from the west. It also means good hiking weather.
Deep red sunrises, on the other hand, are seen when sunlight filters through dust particles in a weather system that has passed. There is also lots of water vapour in the air. It all adds up to a good chance of rain and little soggy hiking.
If there is no dew on grass in the morning, the sky is probably cloudy or there is a strong breeze blowing. Both of these can mean rain.
Halos form around the sun (and moon) as light bends passing through ice crystals in high clouds. These clouds are often seen before an incoming low pressure system, which might bring nasty weather.
And finally, yes, sound does travel better moist air than it does in dry air.
So how does all this affect outdoor adventurers?
Mostly it’s just good fun, but when you’re out in the backcountry for long periods of time, you don’t usually have access to current weather forecasts. Beyond checking the barometer on your watch, watching the skies and knowing the background behind the lore might help you predict the weather.