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The big facts page

126 lightning facts, all checked

Every fact on this site in one place, each linked to its Met Office, NOAA, National Weather Service or NASA source. Our build checks each one against the source text; see the sources page. Things that can change carry the date we checked them.

Jump to: What lightning is | Types of lightning | Thunder and distance | Staying safe | How people are struck | Myths | Around the world | Deaths and injuries

About the numbers

Our sources don’t always round the same way, so we say which one we use. The Met Office gives the speed of sound as 340.29 m/s; NOAA’s table gives 343 m/s in air at 20 °C, and less in colder air. NOAA JetStream says positive lightning is less than 5% of strikes, while the National Weather Service says about 10% of flashes. The Met Office and the National Weather Service also give different advice about crouching outdoors: both agree the answer is to get indoors. Figures that change, such as yearly counts, show the date we checked them.

What lightning is

  1. 1 Lightning is a giant spark of electricity in the atmosphere, or between the atmosphere and the ground. National Weather Service: Lightning science overview
  2. 2 Lightning is a huge electrical discharge that flows between clouds, from a cloud to the air, or from a cloud to the ground. Met Office: Thunder and lightning
  3. 3 A thunderstorm is a series of sudden electrical discharges resulting from atmospheric conditions. Met Office: Thunder and lightning
  4. 4 Thunderstorms develop when the atmosphere is unstable: when warm air sits underneath much colder air. Met Office: Thunder and lightning
  5. 5 Lightning is one of the oldest observed natural phenomena on Earth. NOAA NSSL: Lightning basics
  6. 6 Most lightning, about 75–80%, happens inside the storm cloud itself. NOAA JetStream: How lightning is created
  7. 7 Scientists still haven’t verified exactly how lightning forms. NOAA JetStream: How lightning is created
  8. 8 Inside a storm, collisions make a soft hail called graupel. When graupel bumps into water droplets and ice, electrons are sheared off the rising particles and collect on the falling ones. NOAA JetStream: How lightning is created
  9. 9 As hail falls through the cloud it gains a negative charge, while the ice particles carried upwards gain a positive charge. So the top of the cloud becomes positive and the lower part negative. Met Office: Thunder and lightning
  10. 10 Thunderstorm updrafts can carry air to between 35,000 and 70,000 feet (about 10.7 to 21.3 km). NOAA JetStream: How lightning is created
  11. 11 A stepped leader comes down from the cloud in steps, each one quicker than a blink. It’s invisible to the human eye. NOAA JetStream: How lightning is created
  12. 12 Electrons shoot down from the cloud, cutting through the air at around 270,000 miles per hour. Met Office: Thunder and lightning
  13. 13 The bright flash you see is the return stroke, which carries more than 99% of the light. NOAA JetStream: Lightning FAQ
  14. 14 One flash is usually several strokes, only hundredths of a second apart. Met Office: Thunder and lightning
  15. 15 A lightning bolt is only about 2–3 cm wide, but on average about 2–3 miles long. Met Office: Thunder and lightning
  16. 16 Lightning heats the air to up to 30,000 °C almost instantly: five times hotter than the surface of the Sun. Met Office: Thunder and lightning
  17. 17 The National Weather Service puts it at 50,000 degrees Fahrenheit, 5 times hotter than the surface of the Sun. National Weather Service: Understanding thunder
  18. 18 An average lightning bolt carries about 30,000 amps and has 300 million volts of electric potential. NOAA JetStream: Lightning FAQ
  19. 19 Lightning can have 100 million to 1 billion volts, and contains billions of watts. NOAA NSSL: Lightning FAQ
  20. 20 When lightning hits sand, it can melt it into a glassy rock called a fulgurite, shaped like a twisty tube. NOAA NSSL: Lightning FAQ
  21. 21 Lightning often strikes the same place repeatedly, especially a tall, pointy, isolated object. National Weather Service: Lightning myths
  22. 22 Lightning isn’t only in thunderstorms. It can be seen in volcanic eruptions, extremely intense forest fires, heavy snowstorms and large hurricanes. NOAA NSSL: Lightning FAQ
  23. 23 When thundersnow happens at night, the lightning looks brighter, because the light reflects off the snowflakes. Met Office: Thunder and lightning
  24. 24 Can you have thunder without lightning? No. Thunder is caused by lightning. NOAA NSSL: Lightning FAQ
  25. 25 What’s the difference between a thundershower and a thunderstorm? Technically, there’s none. NOAA JetStream: Lightning FAQ

Types of lightning

  1. 26 Lightning between charges inside the storm cloud is intra-cloud lightning. Lightning between the cloud and the ground is cloud-to-ground lightning. National Weather Service: Lightning science overview
  2. 27 The Met Office lists forked, sheet, streak, ribbon, rocket and pearl-necklace lightning among its types. Met Office: Thunder and lightning
  3. 28 Pearl-necklace lightning is also called “chain lightning” or “beaded lightning”. Met Office: Thunder and lightning
  4. 29 Positive lightning makes up less than 5% of all strikes, according to NOAA JetStream. NOAA JetStream: The positive and negative side of lightning
  5. 30 The National Weather Service says about 10% of lightning flashes are positive flashes. National Weather Service: Positive flashes
  6. 31 Positive lightning can carry as much as 300,000 amperes and one billion volts. NOAA JetStream: The positive and negative side of lightning
  7. 32 A “bolt from the blue” is a cloud-to-ground flash that comes out of the side of a storm and can strike far from it. NOAA NSSL: Lightning FAQ
  8. 33 Sprites flash 25–45 miles (40–75 km) above storms, and elves even higher, at 60–250 miles (100–400 km). Both are often red. NOAA JetStream: The positive and negative side of lightning
  9. 34 You might see lightning and not hear the thunder because the storm is too far away. This is sometimes called “heat lightning”, because it happens most often in summer. NOAA NSSL: Lightning FAQ
  10. 35 Dry lightning is lightning with no rain nearby. It’s more likely to start forest fires. NOAA NSSL: Lightning FAQ
  11. 36 In snowstorms, pink and green are often described as colours of lightning. NOAA NSSL: Lightning FAQ

Thunder and distance

  1. 37 Thunder is the acoustic shock wave caused by the extreme heat of a lightning flash. NOAA JetStream: The sound of thunder
  2. 38 The air in the lightning channel heats so fast that it expands explosively, and that makes the sound. NOAA JetStream: The sound of thunder
  3. 39 Lightning heats the air in its channel to above 50,000 °F in only a few millionths of a second. NOAA NSSL: Lightning FAQ
  4. 40 Thunder is a shock wave for the first 10 yards, then it becomes an ordinary sound wave. NOAA NSSL: Lightning FAQ
  5. 41 The lightning and the thunder clap happen at the same time. You see the flash first because light is far faster than sound. Met Office: Thunder and lightning
  6. 42 The Met Office gives the speed of light as 299,792,458 m/s and the speed of sound as 340.29 m/s. Met Office: Thunder and lightning
  7. 43 In air at 20 °C, sound travels at about 343 metres per second. At 0 °C it’s about 331 m/s. NOAA Global Monitoring Laboratory: Using sound waves (speed of sound table)
  8. 44 A NOAA table of the speed of sound in air: 325 m/s at −10 °C, 331 at 0 °C, 337 at 10 °C, 343 at 20 °C and 349 at 30 °C. NOAA Global Monitoring Laboratory: Using sound waves (speed of sound table)
  9. 45 Sound waves move faster in warm air than in cool air. NOAA JetStream: The sound of thunder
  10. 46 The sound of thunder takes about 5 seconds to travel a mile. National Weather Service: Understanding thunder
  11. 47 Count the seconds from the flash to the thunder. Divide by five for the distance in miles, or by three for kilometres. Met Office: Thunder and lightning
  12. 48 If you count 15 seconds before you hear the thunder, the lightning is 3 miles (5 km) away. NOAA JetStream: Lightning safety
  13. 49 5 seconds = 1 mile, 15 seconds = 3 miles, 0 seconds = very close. National Weather Service: Understanding thunder
  14. 50 Keep in mind that you should be in a safe place while counting. National Weather Service: Understanding thunder
  15. 51 A sharp crack or click means the lightning channel passed nearby. A rumble means it was at least several miles away. National Weather Service: Understanding thunder
  16. 52 Thunder can be heard for a distance of only about 10 miles. National Weather Service: Understanding thunder
  17. 53 Thunder normally has an audible range of up to 10 miles (16 km). NOAA JetStream: The sound of thunder
  18. 54 The Met Office says thunder is rarely heard more than 20 km away. Met Office: Thunder and lightning
  19. 55 Thunder lasts longer than lightning because the sound comes from different parts of the long lightning channel. Met Office: Thunder and lightning
  20. 56 Generally, the louder the thunder, the closer the lightning. Met Office: Thunder and lightning
  21. 57 The snow in a thundersnow storm dampens the sound, so you’ll only hear the thunder within 2 to 3 miles of the lightning. Met Office: Thunder and lightning

Staying safe

  1. 58 There is no safe place outside when thunderstorms are in the area. National Weather Service: Lightning safety overview
  2. 59 When thunder roars, go indoors! National Weather Service: Lightning safety overview
  3. 60 See a flash? Dash inside! National Weather Service: Lightning safety
  4. 61 When you hear thunder, you are already within range of where the next ground flash may occur. Met Office: Stay safe in thunder and lightning
  5. 62 Lightning can strike as far as 10 miles from the centre of a storm. Met Office: Stay safe in thunder and lightning
  6. 63 Lightning can strike outward 10 miles from a thunderstorm. National Weather Service: Lightning science overview
  7. 64 Safe shelter is a substantial building with electricity or plumbing, or an enclosed, metal-topped vehicle with the windows up. National Weather Service: Lightning safety tips
  8. 65 Rain shelters, small sheds and open vehicles are not safe. National Weather Service: Lightning safety overview
  9. 66 Picnic shelters, dugouts and small buildings without plumbing or electricity are not safe. National Weather Service: Indoor lightning safety
  10. 67 Stay in a safe shelter for at least 30 minutes after you hear the last sound of thunder. National Weather Service: Lightning safety tips
  11. 68 Indoors, don’t wash your hands, take a shower or wash dishes during a thunderstorm. National Weather Service: Indoor lightning safety
  12. 69 Indoors, stay away from windows and doors, and don’t lie on concrete floors. National Weather Service: Lightning safety tips
  13. 70 Mobile phones and cordless phones are safe to use indoors. National Weather Service: Lightning safety overview
  14. 71 Telephone lines can conduct electricity, so try to avoid using a landline phone unless it’s an emergency. Met Office: Stay safe in thunder and lightning
  15. 72 Lightning can cause power surges: before the storm, unplug non-essential appliances if you don’t use a surge protector. Met Office: Stay safe in thunder and lightning
  16. 73 You can use remote controls safely. National Weather Service: Indoor lightning safety
  17. 74 Protect your pets: dog houses are not safe shelters. National Weather Service: Indoor lightning safety
  18. 75 Being underneath a tree is the second leading cause of lightning casualties. National Weather Service: Lightning myths
  19. 76 Never shelter under an isolated tree, and never use a cliff or rocky overhang for shelter. National Weather Service: Lightning safety tips
  20. 77 Never lie flat on the ground. National Weather Service: Lightning safety tips
  21. 78 If you’re outside, avoid water, and avoid golf, rod fishing or boating on a lake. Met Office: Stay safe in thunder and lightning
  22. 79 A hard-topped metal car with the windows closed protects the people inside. National Weather Service: Lightning and cars
  23. 80 In a car, the frame acts as a conductive Faraday cage. Soft-top convertibles are the most at risk. Met Office: Stay safe in thunder and lightning
  24. 81 Tents are not safe places in a thunderstorm. National Weather Service: Outdoor lightning safety
  25. 82 At the beach: go to your car! Don’t shelter under beach picnic shelters. National Weather Service: Outdoor lightning safety
  26. 83 At a sports match: get everyone into vehicles or a safe building. Don’t stay in the dugouts: they aren’t safe during lightning. National Weather Service: Outdoor lightning safety
  27. 84 Camping: go to your vehicle! The tent and picnic shelter are not safe places. National Weather Service: Outdoor lightning safety
  28. 85 Lightning victims do not carry an electrical charge and are safe to touch. National Weather Service: Lightning safety overview
  29. 86 The Met Office says that if you’re caught in the open it may be advisable to squat close to the ground, and not to lie down. Met Office: Stay safe in thunder and lightning
  30. 87 The National Weather Service says crouching doesn’t make you any safer outdoors: there is no safe place outside. National Weather Service: Lightning myths
  31. 88 NOAA JetStream: “We don’t recommend the crouch.” NOAA JetStream: Lightning FAQ
  32. 89 Lightning rods don’t stop lightning striking a building. They intercept the strike and give it a safe path to the ground. National Weather Service: Lightning rods
  33. 90 Don’t lie on a garage floor during a storm. National Weather Service: Lightning safety overview

How people are struck

  1. 91 If someone is struck, get help fast: immediate medical attention, including calling the emergency services, starting CPR and using a defibrillator (AED), may be critically important. National Weather Service: How people are struck by lightning
  2. 92 Direct strike: the person becomes part of the main lightning channel. It’s not as common as the other ways people are struck. National Weather Service: How people are struck by lightning
  3. 93 Side flash: lightning jumps from a taller object to a person nearby, often within a foot or two. National Weather Service: How people are struck by lightning
  4. 94 Ground current: the energy spreads out along the ground. This causes the most lightning deaths and injuries. National Weather Service: How people are struck by lightning
  5. 95 Conduction: metal doesn’t attract lightning, but it gives the current a path, through metal wires, plumbing or metal surfaces. National Weather Service: How people are struck by lightning
  6. 96 Streamers: these reach up from the ground as the lightning leader comes down. People caught in streamers are at risk of being killed or injured. National Weather Service: How people are struck by lightning
  7. 97 A lightning bolt can be fatal up to 100 feet (about 30 m) from where it strikes. NOAA JetStream: Lightning FAQ

Myths

  1. 98 Myth: metal attracts lightning. Fact: the presence of metal makes absolutely no difference to where lightning strikes. National Weather Service: Lightning myths
  2. 99 Myth: rubber tyres or rubber-soled shoes protect you. Fact: rubber soles and rubber tyres are not insulators. NOAA JetStream: Lightning safety
  3. 100 Do a car’s rubber tyres protect you if you’re outside, leaning on it? No! It’s the hard metal roof and sides that protect people inside. National Weather Service: Lightning and cars
  4. 101 Myth: lightning victims are “charged”. Fact: the human body does not store electricity. It’s perfectly safe to touch a lightning victim. National Weather Service: Lightning myths
  5. 102 Myth: lightning never strikes the same place twice. Fact: the Empire State Building is hit an average of 23 times a year. National Weather Service: Lightning myths · checked 27 Oct 2026
  6. 103 Myth: if it isn’t raining, you’re safe. Fact: “bolts from the blue” can strike 10–15 miles from the thunderstorm. National Weather Service: Lightning myths
  7. 104 Most people struck by lightning each year are in rain-free areas, miles from the thunderstorm. NOAA JetStream: Lightning safety
  8. 105 Benjamin Franklin’s kite was never struck by lightning! NOAA JetStream: Lightning safety
  9. 106 Myth: lying flat is safer. Fact: lying flat increases your chance of being affected by deadly ground current. National Weather Service: Lightning myths
  10. 107 Myth: lightning flashes are 3–4 km apart. Fact: new data shows half the flashes are about 9 km apart. National Weather Service: Lightning myths
  11. 108 Lightning detection equipment has confirmed bolts striking almost 50 miles away. NOAA JetStream: Lightning FAQ
  12. 109 NSSL describes a “bolt from the blue” that struck a cyclist about 16 km (around ten miles) from the storm. NOAA NSSL: Lightning FAQ

Around the world

  1. 110 Lightning hits somewhere on Earth’s surface about 44 times every second: nearly 1.4 billion strikes a year. Met Office: Thunder and lightning · checked 27 Oct 2026
  2. 111 Lightning strikes the United States about 25 million times a year. National Weather Service: Lightning safety · checked 27 Oct 2026
  3. 112 In the UK, thunderstorms are most common over the East Midlands and the south-east. Met Office: Thunder and lightning
  4. 113 In the UK, thunderstorms can happen at any time of year, but the most severe usually come in summer. Met Office: Thunder and lightning
  5. 114 Lake Maracaibo in Venezuela is Earth’s lightning capital, with an average of about 233 flashes per square kilometre per year (NASA, from 16 years of satellite data). NASA: Earth’s new lightning capital revealed · checked 27 Oct 2026
  6. 115 Lake Maracaibo averages 297 night-time thunderstorms a year, peaking in September. NASA: Earth’s new lightning capital revealed · checked 27 Oct 2026
  7. 116 Africa has the most lightning hotspots of any continent: six of the world’s top ten. NASA: Earth’s new lightning capital revealed
  8. 117 In the US, the central Florida peninsula, from Tampa Bay to Cape Canaveral, has the highest concentration of lightning. NOAA JetStream: Lightning FAQ
  9. 118 Lightning strikes ignite more than half of the acreage burned by wildfires in the US. NOAA NESDIS: Geostationary Lightning Mapper · checked 27 Oct 2026
  10. 119 NOAA’s satellite team says lightning can strike ground as far as 100 miles from a thunderstorm. NOAA NESDIS: Geostationary Lightning Mapper
  11. 120 From space, NOAA’s Geostationary Lightning Mapper updates every 20–60 seconds. Weather radar updates roughly every 5 minutes. NOAA NESDIS: Geostationary Lightning Mapper · checked 27 Oct 2026
  12. 121 NASA’s Lightning Imaging Sensor spotted lightning from orbit by watching a narrow band of near-infrared light around 777 nanometres, even in bright daytime. NASA: Earth’s new lightning capital revealed
  13. 122 Lightning sends out pulses of radio waves called sferics. The Met Office’s LEELA system detects them to locate lightning strikes. Met Office: Thunder and lightning

Deaths and injuries

  1. 123 Lightning kills about 20 people in the United States each year. National Weather Service: Lightning safety · checked 27 Oct 2026
  2. 124 US lightning deaths in 2026 so far: 16 (National Weather Service preliminary figure, last updated 22 Sep 2026). National Weather Service: Lightning fatalities · checked 27 Oct 2026
  3. 125 The National Weather Service puts the odds of being struck in an 80-year lifetime at 1 in 15,300, based on averages for 2009–2018. National Weather Service: How dangerous is lightning? · checked 27 Oct 2026
  4. 126 Only about 10% of people who are struck by lightning are killed, leaving 90% with various degrees of disability. National Weather Service: How dangerous is lightning? · checked 27 Oct 2026