You check the forecast for it. You plan outdoor events around it. You even carry around an umbrella just to deal with it. From major storms to a little drizzle, it’s safe to say that we are all very familiar with rain. But how much do you really know about this common form of precipitation? Rain is such a common occurrence that many of us never stop to think much about it. So, we’ve put together a roundup of facts about rain to help you learn more about this everyday weather phenomenon. Ready to discover some new facts about rain? Then keep reading!
#1 Phantom Rain Exists.
Under certain conditions, rain can fall from the sky but never touch the ground. This happens when rain falling from a cloud evaporates or sublimes as it gets closer to the Earth’s surface. When this phenomenon occurs, a tail or whisp can be seen extending from a cloud in a downwards position. These whisps are referred to as “Virga clouds.” They are most common with cirrocumulus, altocumulus, altostratus, nimbostratus, stratocumulus, cumulus, and cumulonimbus clouds.
#2 Rain Has a Smell.
Most people are familiar with the distinctive scent that comes with rain (the word for it is "petrichor"), but why does this smell occur? Bacteria in the soil release a chemical called geosmin, which the human nose is quite sensitive to. When rain falls on clay, concrete, or dusty soil, it traps tiny air bubbles. The bubbles shoot upwards through the raindrop and create an aerosol that remains suspended in the air. One of the components of the aerosol is geosmin; once it’s released into the air, the scent is carried by the wind and humans are able to smell it. Scientists also think that geosmin could be related to terpenes, the source of scent in many plants, and that rain could bring these fragrances out, further strengthening that fresh-rain scent.
#3 Raindrops Aren’t Shaped Like Teardrops.
Raindrops are usually shown to be teardrop shaped in animated TV shows and other artistic depictions. However, raindrops are not actually shaped like teardrops! When they first form high in the atmosphere, raindrops are spherical. As they begin to fall, their shape changes. The air resistance causes the bottom of the raindrop to flatten and curve. So raindrops aren’t actually teardrop shaped – instead, they resemble the oblong shape of hamburger buns or (in some cases) jelly beans!
#4 The Wettest Place on Earth Receives Over 11,000 mm of Rain Each Year.
Mawsynram is a village located in the state of Meghalaya in India. This village receives the most rainfall of any place in the world. The area gets an average of 467.35 inches (11,871 mm) of rain per year. To put it in context, when taken all together, that much rain would go up to the knees of Rio de Janeiro’s 30m tall Christ the Redeemer statue! But the people of Mawsynram have adapted to life in such a wet place. Outdoor workers wear full-body umbrellas made from bamboo and banana leaves. The locals have even trained the roots of rubber trees to grow into natural bridges, creating a far more long-lasting solution than man-made bridges, which easily rot in the wet climate.
#5 The Least Rainy Place on Earth Isn’t Where You’d Think.
If asked what the least rainy place on Earth is, you might guess somewhere hot and dry, such as the Sahara Desert. Nope! The least rainy place on Earth is actually Antarctica, which receives a mere 6.5 inches of rain (or snow!) per year. For a place to be classified as a desert, it has to be barren, dry, and hostile to life, but it does not have to be hot. This means that Antarctica is actually the largest desert on Earth based on its extremely inhospitable climate and low levels of precipitation. In fact, the interior regions of Antarctica receive less than 51 mm of precipitation (including both rain and snow) per year!
#6 Rain Is Not a New Phenomenon.
Scientists have discovered fossils that contain indentations of raindrops. These fossils date back to 2.7 billion years ago, proving that it has been raining on Earth for a very long time. Wondering how these fossils of raindrops were created? Billions of years ago, early liquid rain fell on layers of volcanic ash. Then more volcanic ash was deposited on top, which preserved the indentations made by the raindrops. Over time, erosion exposed these fossils once again and they were discovered by modern scientists.
#7 Rain Often Starts Out as Snow.
The Bergeron or “cold rain” process is responsible for much of the rain that occurs outside of the tropics. In these areas, clouds are often a mix of ice crystals and super-cooled water drops. Eventually, the ice crystals (snow) will fall toward the ground. However, the type of precipitation we experience close to Earth’s surface depends on the temperature of the atmosphere from the base of the cloud to the ground. This means that the rain we experience on Earth can start out as snow – even when it is a hot summer’s day!
Want to learn even more facts about rain? Check out this cool video!