The Firefall is a spectacular natural phenomenon that only occurs in one place in the world, Yosemite National Park, California. Every year in February, a waterfall turns into a blazing flow for which tourists travel from all over the world. Every year, between February 10 and 28, the famous Horsetail Fall in Yosemite National Park, United States, becomes the scene of an optical phenomenon unique in the world. At this time, the sunset sends rays that are positioned in exactly the right place to illuminate the long trickle of water, whose peak rises to 610 meters above sea level. Seen from the bottom of the El Capitan cliff, it then takes on the appearance of a very luminous orange flame, or even lava, hence its nickname of firefall, firefall in English. The “fire” begins to take shape between 5 and 15 minutes before sunset, that is to say around 5:30 p.m. Under what conditions is the cascade of fire the most spectacular? If the period during which the phenomenon occurs may vary slightly, the weather conditions which allow its observation also: the presence of clouds or fog can destroy any hope of witnessing to a waterfall of fire. Likewise, the flow of fire can only occur if there is enough water. In case of drought, there is therefore almost nothing to see. But, after the torrential rains and the abundant snowfalls associated with the passage of several atmospheric rivers on California, the spectacle was grandiose in this month of February 2023. The water was currently able to flow in an abundant way along the cliff of Yosemite: the sun can, in this case, perfectly reflect on the trickle of water. In some years, another fire cascade happens in the fall, and not just in the winter. For this, a rather humid summer is necessary, which is very rare in California.