Since the middle of 2015, meteorologists have warned that El Niño could bring unusually wet weather to Paraguay, Uruguay, Argentina, and southern Brazil. The warnings have proven to be prescient.

In December and January, heavy summer rains swamped this part of South America causing the Uruguay, Paraguay and Paraná rivers to swell beyond flood stage. As of January 15, 2016, floods had displaced more than 150,000 people in what some observers are calling the worst floods to affect the region in decades.

Paraguay has been hit the hardest. More than 100,000 people have been evacuated, mostly from Asunción, the capital city. Many of these people are now living in temporary shelters throughout the city. Some of the hardest hit neighborhoods were Los Baños and Bañado Norte, both of which are located along the river.

On January 7, water levels in Asunción rose as high as 7.84 meters (25.72 feet). Authorities issue flood warning when water reaches 4.5 meters. By the time the Advanced Land Imager (ALI) acquired this image on January 12, 2016, waters had dropped to 7.6 meters, still well above flood stage. For comparison, the lower image shows the same area on January 12, 2014, when water levels were more typical.

Even as waters subside, public health threats will persist. In January, Paraguay’s Ministry of Public Health and Social Welfare declared an alert for Dengue, Chikungunya and Zika, viral diseases spread by mosquitoes.

Other NASA satellites, Aqua and Terra, carry sensors that collect data that can be used to produce near real-time flood maps. Flood maps including Asunción are available here. See daily satellite images of the flooded area by viewing the 7-2-1 band combination of the Moderate Resolution Imaging Spectroradiometer in the Worldview browser.

NASA Earth Observatory images by Jesse Allen, using EO-1 ALI data provided courtesy of the NASA EO-1 team and Landsat data from the U.S. Geological Survey. Caption by Adam Voiland.