San Juan, like the rest of the Cuyo, though even more so, is prone to the zonda, a legendary dry wind that blows down from the Andes and blasts everything in its path like a blowtorch. It’s caused by a thermal inversion that arises when wet, cold air from the Pacific is thrust abruptly up over the cordillera and suddenly forced to dump its moisture, mostly in the form of snow, onto the skyscraper peaks before helter-skeltering down the other side into the deep chasm between the Cordillera Principal and the pre-cordillera, which acts like a very high brick wall. Forced to brake, the zonda rubs against the land like tyre-rubber against tarmac, and the resulting friction results in blistering temperatures and an atmosphere you can almost see. Mini-tornadoes can sometimes also occur, whipping sand and dust up in clearly visible spirals all along the region’s desert-like plains. The Cuyo’s answer to the Föhn, mistral or sirocco, ripping people’s nerves to shreds, the zonda is one of the world’s nastiest meteorological phenomena. Although it can blow at any time of year, the zonda is most frequent in the winter months, particularly August, when it can suddenly hike the temperature by ten to fifteen degrees in a matter of hours.