Leaves flipping over before it rains? Does this happen, or is it a mythical occurrence among the many we keep hearing about?
Before we water it down as a myth, we must go through history and understand why our forebears held on to this somewhat scientific phenomenon.
Before technology took over, early man relied on natural and traditional means to decipher a significant change in weather or the onset of a new weather regime like drought.
This was before weather forecast tools and meteorological stations were invented to predict the weather.
Could leaves flipping before it rained be a forecast for a major weather change, and what is the reason behind it?
This article looks at this puzzling question in-depth and offers a more scientific assessment of the same.
Do Leaves Flip Over Before it Rains and Why?
Leaves flipping over is common among several plants. According to weather lore and old wives’ tales, it is a natural indicator of a major change in the weather.
It indicates a transition from a drought to a rainy period. Precisely, the leaves flip to show their silvery and light green underside, which happens due to factors such as
- A change in the prevailing wind
- Increase in humidity levels
- Low moisture
How exactly do the above factors come into play? Let’s take a deeper dive.
1. Wind
Tree leaves typically grow and align according to the direction of the prevailing wind in a given area.
However, if a storm occurs in an area, the wind direction will likely change, causing the leaves to ruffle backward. This exposes their light green underside.
Heavy rains usually follow storms providing some credence to the lore.
2. Humidity
Another factor that would cause leaves to flip before it rains is increased humidity levels. Humidity has a softening effect on leaves, resulting in them hanging limply over branches.
They also tend to curl, forecasting oncoming rain. Curling exposes their undersides.
This is common in such plants as Marple trees, Poplars, Oak, the Scarlet Pimpernel, and Pinecone.
Pinecones absorb moisture under damp or humid conditions, making the scales flexible. In dry conditions, they typically shrivel up.
The other plant that closes itself up under heavy humidity is the Scarlet Pimpernel heralding the coming of rains. It has earned the name the “poor man’s weather glass.”
Humidity levels could become elevated before it rains, adding more weight to the correctness of the lore.
3. Low Moisture
In some plants, excessive heat and low moisture are why the leaves curl to expose their underbelly. For instance, tomato leaves will twist and curl when exposed to high temperatures.
It is a physiological process in self-defense against further water loss.
This isn’t something connected with the onset of rains. However, high temperatures lead to water evaporation from nearby bodies and result in precipitation which we usually call rain.
Are we contradicting ourselves here? Not sure.
Do Plants have Weather Predicting Abilities?
Scientists have come to the consensus that some plants can predict the weather. The old saying goes, “ When leaves show their undersides, be very sure rain betides.”
Joint research by Chinese and European researchers gives credence to this assertion and proves that a range of plants can sense changes in climatic conditions.
Last Word
We hope you now understand why leaves turn over or flip before it rains. According to folklore, it’s a sign that rain is imminent.
However, the primary factors affecting leaf flipping are changes in the prevailing wind, high humidity, and low moisture levels induced by excessive heat.
These factors could indicate a major weather change, proving there is some truth to the old saying.
