Rare Snowstorms Blanket Chile's Atacama Desert as El Niño Strengthens

A series of winter storms swept northern Chile in August 2026, dropping unusual snow on the Atacama Desert, one of Earth's driest places. Similar snow fell in 2025 and 2011, but one storm reached remarkably far, spreading from the Andes to the Pacific coast. NASA and USGS's Landsat 8 and Landsat 9 satellites captured the change in images taken August 6 and August 14, before and after the storm.

The images show the Chajnantor plateau, home to the Atacama Large Millimeter/submillimeter Array (ALMA), one of the world's most powerful radio telescopes. Heavy snow and wind forced ALMA to suspend operations and enter a protective survival mode. A second storm later that month spread snow even further; an August 19 image from NASA's Terra satellite showed it reaching from the Andes across the Atacama toward the coast near Antofagasta, and nearby observatories paused.

Much of the region's winter rain comes from cutoff lows, systems that break from the jet stream. René Garreaud, an atmospheric scientist at the University of Chile, said a cutoff low caused the 2025 snowfall too, but this one split from an unusually large trough spanning much of the Southern Hemisphere. With plentiful coastal moisture, it brought rain and snow from offshore to the Andes, at levels Garreaud called "rarely seen" there.

In Taltal, nearly 40 millimeters (1.6 inches) of rain fell over three days, roughly 10 times the city's average annual rainfall — events Garreaud said happen "only a few times, if any, per decade." Mudflows and flooding that followed affected thousands of people and damaged hundreds of homes, according to Chile's National Disaster Prevention and Response Service (SENAPRED).

Garreaud pointed to the strengthening El Niño as a backdrop. During El Niño, the subtropical Pacific high that normally keeps the region dry weakens, while a blocking high grows more likely farther south, pushing Southern Hemisphere storms closer to the equator and into areas usually extremely dry.