Made of crystals of water ice, noctilucent clouds are most commonly observed in the summer months at latitudes between 50° and 70° north and south of the equator and only when the Sun is below the horizon. They are the highest clouds in the Earth’s atmosphere at around 80 kms. These clouds refract light at dusk when the Sun has already set, illuminating the sky with seemingly no light source.
No 5. Penitentes
Known as penitentes due to their resemblance to processions of white-hooded monks, these ice spikes are commonly found in mountain glaciers and can be from a few centimeters to a few meters in height.
No 4. Ice Circles
This is a natural phenomenon that occurs in slow moving water in cold countries. These circular slabs of ice rotate slowly in the water and have frequently been observed in Scandinavia and North America. There are ice circles that are an amazing over 500 feet in diameters and they can also at times be found in clusters and groups of different sizes.
No 3. Supercells
Also known as the fire devil or fire tornado, Supercells are continuously rotating updrafts deep within a severe thunderstorm. These storms can last for hours on end can propagate too; splitting up into two storms going in different directions. Supercells occur within a mesocyclone and can form anywhere in the world, given the right conditions.