File:Popcorn Clouds in Brazil (MODIS 2024-04-09).jpg

English: Dramatic sheets of popcorn cloud covered the forests of the Brazilian states of Mato Grosso do Sul and Sao Paulo on April 3, 2024. The Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Aqua satellite acquired this true-color image on the same day. Although clouds dominate the image, the skies over the Paraná River remain clear.

In hot, humid regions, vegetation can function a bit like cloud machines. Trees and plants release moisture into the air through transpiration. As heat from the Sun beats down during the day and warms the surface, this moisture rises in the atmosphere, cools, and condenses into small, puffy cumulus clouds. Sheets of these clouds—sometimes called popcorn clouds—typically spring up in mid-morning over tropical forests. They peak in the late-afternoon and fade by the evening, often dropping rain in the process.

Bodies of water, on the other hand, do not change temperature as rapidly; the water remains cooler even during full Sun exposure. The water does not heat up enough to significantly warm the air above it, preventing air from rising to make clouds.