My wife and I got lucky on Monday 2/22, on our first try to see Fire Fall, which can happen in 2nd half of February on Horsetail Fall in Yosemite. This is not the same as the environmentally questionable practice that ended in 1968, after nearly 100 years of dumping burning embers off Glacier Point, that I saw once from Yosemite Valley in the 1960s. This natural Fire Fall was first photographed by Galen Rowell in 1973.
Besides getting a reservation to enter the Park, it takes a sunset without clouds, enough water for falls to be flowing and enough warmth so it's not frozen. We barely had enough water, but sunset also lit up some of the mist the wind was moving around. That is El Capitan to the left of Horsetail Fall. We had to walk about 2 miles each way from where we parked to our viewing point. There was some snow in the shade on some of paths in the 4,000' elevation valley. The first photo is from an iPhone as my camera, which took the second one, was having trouble with the light and I have not had to use it much in manual mode. Pictures where taken about a minute apart.