Rare, Widespread Snowfall in the Atacama Desert

In August 2026, consecutive winter storms brought an unusual snow cover to parts of the Atacama Desert in northern Chile. While the region has experienced snowfall before, notably in 2025 and 2011, one of the 2026 events was exceptionally extensive, reaching from the Andes mountains towards the Pacific coast.

The Operational Land Imager (OLI) on NASA-USGS Landsat 8 and Landsat 9 satellites captured these images, showing the Chajnantor plateau in the Altiplano-Puna volcanic complex, home to the Atacama Large Millimeter/submillimeter Array (ALMA). Due to the snow and high winds, ALMA temporarily ceased operations and entered a protective mode.

Another storm later in August covered an even larger area. An image from NASA's Terra satellite, equipped with the Moderate Resolution Imaging Spectroradiometer (MODIS), on August 19, 2026, revealed snow stretching from the Andes across the hyper-arid desert core and nearing the Pacific coast south of Antofagasta. Several astronomical observatories in this coastal region also paused their operations during this event.

The region's winter precipitation often comes from "cutoff lows," low-pressure systems that detach from the jet stream. According to atmospheric scientist René Garreaud from the University of Chile, the late-August 2026 storm originated from a cutoff low associated with an unusually large trough that spanned a significant portion of the hemisphere. This atmospheric disruption, combined with moisture from the coast, led to precipitation over a broad area, including offshore, coastal, desert, and Andean regions, with amounts rarely seen in this extremely dry environment.

While some areas received rain instead of snow, Taltal on the northern coast recorded nearly 40 millimeters (1.6 inches) of rain in three days, significantly exceeding its annual average. Such events are infrequent, occurring only a few times per decade.

The heavy rainfall triggered destructive mudflows and flash floods in northern Chile. The National Disaster Prevention and Response Service (SENAPRED) reported thousands of people affected and hundreds of homes damaged.

Garreaud noted that a strengthening El Niño provided the backdrop for this unusually wet winter in north-central Chile. El Niño events weaken the subtropical Pacific high, which typically keeps the region dry, and promote the formation of a blocking high in the South Pacific, shifting the Southern Hemisphere storm track northward. This contributed to the significant rainfall and snowfall observed.

References & Resources

CR2 (2026, July 23) The extreme event of July 15-20, 2026, within the context of the developing El Niño. Accessed August 26, 2026.
NASA Earth Observatory (2025, July 19) Rare Snowfall in the Atacama Desert. Accessed August 26, 2026.
National Weather Service, Climate Prediction Center (2026, August 13) El Niño/Southern Oscillation (ENSO) Diagnostic Discussion. Accessed August 26, 2026.
The Watchers (2026, August 18) Snow and 90 km/h (55 mph) winds suspend ALMA observations in the Atacama Desert, Chile. Accessed August 26, 2026.