There is a myth that lightning never strikes the same place twice. However, in one storm the Empire State Building in New York was struck 15 times in 15 minutes.

Air moving within the cloud, causes huge differences in the electrical distribution. The bottom of the cloud develops a negative charge and the top, positive. These electrical differences attract each other, so an 'electrical discharge' is produced within a cloud, between two clouds or to the ground. This discharge we see as lightning.

This discharge is just the same as rubbing your feet on the carpet then touching something. You hear a sound and feel a bit of a tingle. If you turn the light off, you will even see a tiny lightning bolt. Of course, real lightning from thunderstorms is far more powerful. One lightning bolt can reach 30,000C, five times hotter than the sun. Air can often smell 'burnt' after a lightning strike, as this huge amount of energy can alter molecules in the air. This heating also causes thunder. The air rapidly expands and then contracts, causing vibrations in the air. These vibrations, or sound waves, we hear as thunder.

As lightning is seen and thunder heard, lightning travels at the speed of light, and thunder at the speed of sound. The difference in these speeds is so great that light could travel right round the world before sound finished the 100m sprint. This speed difference provides an easy way to see how far away the lightning struck. Count the seconds between the lightning and the thunder, each second represents 300m.

It is estimated that 44,000 thunderstorms happen everyday world-wide, producing 100 lightning flashes every second. That's 8.6 million strikes every single day. Lightning, being such an enormous amount of unpredictable power, can cause great havoc; forest fires, explosions and even death. However, there is only about a one in 3 million chance of being struck by lightning, so it's not something that we need to worry about. Even so, I still wouldn't advise standing on the Empire State Building in a thunderstorm.

Other features in the Weather Basics series
Air Pressure
Clouds
Day and Night
Fog and Mist
Fronts
Frost
High Pressure
Humidity
Jet Streams
Low Pressure
Mirages
Northern Lights
Rain or Showers?
Thunder
Watercycle

Other Features: Air Pollution Air Pressure Clouds Clouds, Nature Of Clouds, Types Of Day in the life of Helen Young Day & night Driving E-met: your weather Flooding Fog Fronts Frost Frost and Snow Frost Fairs Gardening Weather Global Warming - Overview Global Warming - What We Can Do Jet streams Hibernation High Pressure History of Weather Broadcasting Humidity Ice Age - part 1 Ice Age - part 2 Low Pressure Migration Mirages Motorbike Weather Napoleon Russia Northern Lights Our Graphics Our Indices Our Symbols Pollen Forecast Pressure Rain or Showers? Rain, Drizzle and Fog Royal Met. Society, The Scuba Diving Snowmen Sun Index Solar Energy Snowflakes Thunder Water cycle Winter on the Roads Worst Winters Water Energy Wind energy Year so far