The Ozone Laboratory at the city’s University of Magallanes said that the progressively higher sun angles as summer approaches and a peak in ozone depletion passing over the southern tip of South America would combine to create the danger.
People were advised to limit exposure to the sun, use sunscreen and wear protective sunglasses while outdoors.
The health ministry called on parents to pay particular attention to children and teenagers, saying they must be protected from sun exposure.
The stratospheric ozone hole over Antarctica has recently developed an elongated shape, allowing its edges to pass over populated areas of southern Chile and Argentina as it spins and undulates.
Punta Arenas is often referred to as the southernmost city in the world, making it particularly prone to the effects of the ozone hole.
The ozone observatory there regularly launches balloons with instruments to measure UV levels at various altitudes.
Graphic Data: Ozone Hole Watch (NASA)