Thunderstorms and lightning

100 lightning bolts every second

Right now, this minute, there are 2,000 thunderstorms on Earth and 100 lightning bolts every second! Lightning is a giant electric spark inside a cloud — 5 times hotter than the Sun's surface. Thunder is the sound of lightning heating the air so fast that it explodes. Light travels faster than sound: when you see lightning, count the seconds until thunder — every 3 seconds = 1 km. On the globe, most lightning is over Africa and the Amazon — where it's hot and humid.

Thunderclouds (cumulonimbus) form when warm moist air rises, reaching 12–18 km. Ice crystals and hailstones collide and separate charge: the cloud top becomes positive, the base negative; at 100 million volts a discharge occurs — lightning (30,000 °C, 0.2 seconds). Thunder is the shock expansion of the air. The planet sees 8 million lightning strikes a day; the most are over Lake Maracaibo in Venezuela (260 nights a year, 28 strikes an hour), the Congo Basin and Singapore. 80% of lightning stays within clouds; ground strikes pick tall objects. The Burj Khalifa is hit 20 times a year. About 2,000 people die each year; inside a car is safe (a Faraday cage). Lightning 'fertilises' soil with nitrogen. In Uzbekistan thunderstorms are common in spring in the foothills.

Fun facts

• Lightning is 5 times hotter than the Sun's surface — 30,000 °C.
• Over one lake in Venezuela, lightning strikes 260 nights a year — the 'everlasting storm'.
• You're safe from lightning inside a car — the metal carries electricity around you.