Earlier, i spoke to dr matt patterson, whos a Postdoctoral Research assistant in Atmospheric Physics at the University Of Oxford and has been following the winter heatwave. He said this is not a common occurance. Its really quite unusual to see a heatwave of this magnitude in the winter. As you said, weve seen temperatures of 38 degrees in some andes towns when we would expect to see temperatures of 10 15 degrees at this time of year. So really quite unprecedented. In terms of the magnitude, 20 degrees more than average, thats comparable with Summer Heatwaves that weve seen in the southern United States, Southern Europe and china this year. Can you explain in basic terms what exactly is causing this heatwave in winter . Certainly. Its a High Pressure system just to the east of the andes, which is basically dragging warm air down from the tropics and bringing that heat down towards chile and argentina. That High Pressure is also compressing the air, much like when you pump up a bike tyr