Lightning and thunder Cloud-to-cloud and cloud-to-ground lightning. Lightning heats the surrounding air so rapidly that it expands explosively as powerful supersonic pressure waves. As they spread through the atmosphere, the waves weaken and slow, becoming sound waves that are heard as thunder. (more) Why Is Thunder So Loud? Written by Anoushka Pant Anoushka Pant holds a degree in elementary education, with a focus on mathematics, education, and psychology, from Miranda House, University of Delhi. Anoushka Pant Fact-checked by Britannica Editors Encyclopaedia Britannica's editors oversee subject areas in which they have extensive knowledge, whether from years of experience gained by working on that content or via study for an advanced degree.... Britannica Editors Last updated Mar. 12, 2026 •History Lightning and thunderCloud-to-cloud and cloud-to-ground lightning. Lightning heats the surrounding air so rapidly that it expands explosively as powerful supersonic pressure waves. As they spread through the atmosphere, the waves weaken and slow, becoming sound waves that are heard as thunder.© Stockbyte/Getty Images You know that moment: The sky flashes—and boom! Windows rattle. Your heart does a little jump. Thunder isn’t the “noise of electricity.” It’s the set of sounds resulting from air being...

　　.eb-448-paywall-overlay { position: relative; background: white; border: 2px solid #93c5fd; border-radius: 16px; text-align: center; box-shadow: 0 4px 8px 0px #bfdbfe; width: 100%; overflow: hidden; } .eb-448-paywall-overlay-padding { padding: 40px 48px; } .eb-448-paywall-simple { border: 2px solid #93c5fd; } .eb-448-decorative-left-simple, .eb-448-decorative-right-simple { position: absolute; top: 50%; transform: translateY(-50%); } .eb-448-decorative-left-simple { left: 0px; transform: translateY(-50%) scaleX(-1); } .eb-448-paywall-simple .eb-448-decorative-right-simple { right: 0; } .eb-448-paywall-content { position: relative; z-index: 15; } .eb-448-header-section { display: flex; align-items: center; justify-content: center; gap: 12px; margin-bottom: 8px; } .eb-448-features { display: flex; justify-content: center; align-items: center; gap: 12px; margin-bottom: 32px; font-size: 14px; color: #525252; } .eb-448-features-simple { color: #6b6b6b; } .eb-448-feature-free-trial { display: flex; align-items: center; gap: 12px; color: black; } .eb-448-feature-secondary { display: flex; align-items: center; gap: 12px; } .eb-448-feature { font-weight: 600; } .eb-448-feature.simple { font-weight: 400; } .eb-448-feature.bold { color: balck; font-weight: 700; } .eb-448-feature.blue { color: #14599d; } .eb-448-divider { color: #cbd5e0; font-weight: 300; } .eb-448-unsubscribe-text { color: #525252; margin-bottom: 8px; font-size: 14px; font-weight: 600; } .eb-448-unsubscribe-text-simple { font-weight: 400; color: #6b6b6b; } .eb-448-decorative-left { position: absolute; top: 0; left: 0; height: 100%; z-index: -1; } .eb-448-decorative-right { position: absolute; right: 0; top: 0; height: 100%; } .eb-448-decorative-image { height: 100%; } .eb-448-decorative-mobile { width: 100%; display: none; img { width: 100%; } } @media (max-width: 672px) { .eb-448-features { gap: 8px; font-size: 12px; } .eb-448-unsubscribe-text { font-size: 12px; } .eb-448-decorative-left, .eb-448-decorative-right { display: none; } .eb-448-decorative-mobile { display: flex; } .eb-448-paywall-overlay-padding { padding: 20px 24px; } .eb-448-features-simple { flex-direction: column; } .eb-448-feature-free-trial .eb-448-divider { display: none; } .eb-448-thistle-icon { filter: blur(2px); } }

　　Discover the world with Britannica Subscribe to Continue Reading Free Trial | No Ads | Exclusive Content Unsubscribe Anytime!

　　Explore Subscriptions