Yosemite's ‘firefall’ optical illusion is happening right now

Tourists have flocked to Yosemite’s to witness “firefalll,” the phenomenon at Horsetail Fall where the waterfall looks like a stream of orange lava. The "firefall" occurs for two hours out of the day, generally between February 16-23, when the setting sun’s light hits the waterfall at exactly the right angle, resulting in a fiery show.

This optical illusion doesn’t happen every year. Cloudy weather conditions have hampered the “firefall” in past seasons. But when conditions are perfect, like they are right now, Horsetail Fall boasts a red and orange show come sunset.

According to SFGate, “the occurrence has been regarded by at least one photographer as the "worst-kept secret on the internet," and as an event that leads lots of people to stake out a spot to watch and snap pictures of the firefall.”

One look at Horsetail Falls Instagram geotag will tell you that this year is a great year to check it out. The recent storms have provided even more water, so if you’re looking for something to do this weekend, head to Yosemite.

For those of you who can’t make it, check out these shots of the glowing fall.

• Yosemite's rare 'firefall' phenomenon attracts tourists and photographers [SFGate]