A natural phenomenon is a non-artificial event in the physical sense, and therefore not produced by humans, although it may affect humans. Common examples of natural phenomena include volcanic eruptions, weather, and decay. Most natural phenomena, such as rain, are relatively harmless so far as humans are concerned.
There are various types of natural phenomena, which include Meteorological phenomena, weather, including hurricanes, thunderstorms and tornadoes, and geological phenomena, including volcanic activity and earthquakes. So here I have compiled some of the most fascinating natural phenomena. 
Aurora Borealis

Undoubtedly one of the most beautiful events to occur in our world, the Aurora Borealis, also known as the Northern Lights, has both astounded and amazed people since it was first discovered.
Mammatus Clouds
They are a cellular pattern of pouches hanging underneath the base of a cloud. Composed primarily of ice, Mammatus Clouds can extend for hundreds of miles in each direction. Mammatus clouds are often harbingers of a coming storm or other extreme weather system.
Red Tides
More correctly known as an algal bloom, the so-called Red tide is a natural event in which estuarine, marine, or fresh water algae accumulate rapidly in the water column and can convert entire areas of an ocean or beach into a blood red color.
Penitentes
These amazing ice spikes, generally known as penitentes can be found on mountain glaciers and vary in size dramatically. Initially, the sun’s rays cause random dimples on the surface of the snow.

Sailing Stones

Rocks weighing up to hundreds of pounds have been known to move up to hundreds of yards at a time. Some scientists have proposed that a combination of strong winds and surface ice account for these movements.

SuperCells

Super cell are usually isolated storms, which can last for hours, and sometimes can split in two, with one storm going to the left of the wind and one to the right. They can spout huge amounts of hail, rain and wind and are often responsible for tornados.
Fire Whirls
A fire whir is a rare phenomenon in which a fire, under certain conditions acquires vertical vortices and forms a whirl of a vertical orientation rotating column of air. They can be as high as 30 to 200 ft tall.
Ice Circles
Ice Circles are formed when surface ice gathers in the center of a body of water rather than the edges. A slow moving river current can create a slow turning eddy, which rotates, forming an ice disc. These ice circles have been seen with diameters of over 500 feet.
Gravity Waves
The undulating pattern of a Gravity Wave is caused by air displaced in the vertical plain, usually as a result of updrafts coming off the mountains or during thunderstorms. Nature then tries to restore the fluid changes caused by updrafts within the atmosphere, which present in a visible oscillating pattern within the cloud.
Fire Rainbow
Fire rainbow appears when the sun is high in the sky and its light passes through diaphanous, high-altitude cirrus clouds made up of hexagonal plate crystals.