Manaus sits at the heart of the Amazon rainforest, where the Rio Negro meets the Amazon River, and it receives an enormous amount of rain, averaging around 2,300 mm (about 91 inches) a year. Rainfall is heaviest from December through May, when the combined flow of the surrounding rivers can rise dramatically, sometimes flooding riverside neighborhoods and the famous floating docks that adjust with the water level. Daily tropical thunderstorms are the norm through much of the year, often building quickly in the afternoon heat and dropping intense, short-lived downpours. Because the region’s flood risk comes from both the cumulative rise of the rivers over weeks and the sudden intensity of individual storms, radar is particularly useful for the second part: seeing a heavy cell building over the basin before it reaches the city. Brazil’s SIPAM Amazon monitoring system, alongside INMET, maintains radar coverage across this remote but closely watched region.
Learn more: Flash Flood Warning Signs on Radar · Open the full Rain Map