Mammatus clouds are pouch-like protrusions hanging from the undersides of clouds. You’ll usually find them under thunderstorm anvil clouds. But you might see them under other types of clouds as well. They’re composed primarily of ices, and groups of them can extend hundreds of miles in any direction. But they’re fleeting, remaining visible in your local sky for perhaps 10 or 15 minutes at a time.
People associate these cloud pouches with severe weather. And it’s true; they typically appear around, before or after a storm.
In fact, most clouds are formed by rising air. But mammatus clouds are interesting in part because they’re formed by sinking air.
They appear ominous. And they do signify storms. But, in a way that’s so common in nature, their dangerous aspect goes hand-in-hand with a magnificent beauty.
Beautiful, bubbling clouds from 2023
Mammatus clouds from 2022
Mammatus clouds from 2021
Images from 2020
Bottom line: Mammatus clouds look like bubbling, low-hanging clouds. They’re often associated with thunderstorms. Learn more about them here and see photos.
Our Editor-in-Chief Deborah Byrd works to keep all the astronomy balls in the air between EarthSky's website, YouTube page and social media platforms. She's the primary editor of our popular daily newsletter and a frequent host of EarthSky livestreams. Deborah created the EarthSky radio series in 1991 and founded EarthSky.org in 1994. Prior to that, she had worked for the University of Texas McDonald Observatory since 1976, and created and produced their Star Date radio series. She has won a galaxy of awards from the broadcasting and science communities, including having an asteroid named 3505 Byrd in her honor. In 2020, she won the Education Prize from the American Astronomical Society, the largest organization of professional astronomers in North America. A science communicator and educator since 1976, Byrd believes in science as a force for good in the world and a vital tool for the 21st century. "Being an EarthSky editor is like hosting a big global party for cool nature-lovers," she says.
Like what you read? Subscribe and receive daily news delivered to your inbox.
Thank you! Your submission has been received!
Oops! Something went wrong while submitting the form.