Here's What Causes Yosemite's Famous 'Horsetail Firefall' To Look Like Flowing Lava

The Horsetail waterfall also known as the Fiery Waterfall in Yosemite National Park, US, is a sight to behold; for anyone travelling to the US anytime soon, this should definitely be on your bucket-list.

The breathtaking sight takes place exclusively in the month of February every year. An incredible video apparently showing a river of fire falling down a cliff has gone viral on Twitter.

¡°Firefall¡± at Horsetail Fall in Yosemite National Park, California, looks like a scene from a fantasy movie. But, it is an ordinary waterfall, which is illuminated by the sunset, that gives it a fiery glow. pic.twitter.com/kP2aFmM6Cg

¡ª Domenico Calia (@CaliaDomenico) January 19, 2020

For those unaware, the phenomenon became popular in 1973 after National Geographic photographer Galen Rowell snapped a startling image of the glowing light.

The waterfall is actually a phenomenon that comes from light-and-water, the setting sun strikes the waterfall in February and that's what gives the water the orange, lava-like glow. Horsetail Fall tumbles about 2,000 feet down the eastern side of El Capitan in Yosemite Valley.

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#Repost @michaellaxphoto A Song of Fire and Ice After several years of missing it, I finally witnessed Yosemite¡¯s famed ¡®firefall¡¯ spectacle yesterday! What looks like lava pouring off a cliff is actually the setting sun¡¯s last light projecting onto a waterfall plunging 1,500 feet to the ground. The mesmerizing warm glow stuck out like a sore thumb against the cold, dark granite wall of El Capitan. I was blown away at the hundreds of people alongside me bearing the cold for hours as we all waited for the magic to happen. And when it finally did...the forest erupted in camera clicks and cheers¡ªit was awesome to be a part of. I¡¯m thrilled to have scratched this off my bucket list and I highly recommend you add it to yours. FYI, this phenomenon only occurs in mid-to-late February and needs just the right conditions to come together: a clear sky for the sun to break through and enough snowmelt for the waterfall to flow. #yosemite #firefallyosemite #firefall #landscape #rei1440project #drinkinbrosadventures

A post shared by DB¡¯s Adventures & Travel (@drinkinbros_outdoors_) on Mar 3, 2019 at 3:27pm PST

But for those who are keen on witnessing this beauty, be warned, it lasts for a mere 10 minutes. And for the phenomenon to occur the conditions have to perfect. According to LA Times, 'Skies must be clear; the slightest haze or passing cloud around sunset time can ruin the effect.'

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¡°Molten Water¡± - Fire. Fall. - February 22, 2019 Sony A7ii, Canon FDn 200mm f/2.8 ISO 100, f/8, 1/20sec - #firefall #yosemite #moltenwater

A post shared by Daniel Berson (@bersonphotos) on Mar 4, 2019 at 9:16pm PST

In 2020, the firefall is expected to be visible roughly between February 13 and 29, with the strongest light from February 19-22.