World Lightning: Thunderstorms and human population

Time again to talk about the weather: Britain is suffering under heatwave conditions (also known as summer in other parts of the world), with the ongoing high temperatures and developing clouds going along with an increased humidity slowly increasing the risk for thunderstorms. Thunderstorms are not an uncommon phenomenon on the British Isles, but they are much less common and much less severe compared to other regions experiencing similar conditions much more frequently and more intensively. The Met Office explains that “Owing to the fact thunderstorms are created by intense heating of the earth’s surface, they are most common in areas of the globe where the weather is hot and humid. Land masses therefore experience more storms than the oceans and they are also more frequent in tropical areas than the higher latitudes. In the UK thunderstorms are most common over the East Midlands and the south-east.
As it happens to be, the part most prone to thunderstorms in Britain is also the most densely populated region. Comparing this to other parts of the world, it can be seen that some of the most risky regions are also some of the very densely populated places. In Europe, which is overall densely populated in many parts, the most affected areas are the people living in the Mediterranean countries, although the European population in general is amongst the least affected by thunderstorms when comparing this to areas such as the southern edge of the Himalayas in India – densely populated and experiencing very intensive thunderstorms. These details only emerge when changing the projection of data collected on lightning flashes from a conventional land area map (where this part of India for instance remains comparably small) to a gridded population cartogram. The following map shows the intensity of lightning flashes displayed as the number of flashes per square kilometre per year in each of the grid cells, while the distortion of the grid cells reflects the global population distribution, so that the most and least exposed populations are highlighted in this visualisation:

Equal population projection map of
(click for larger version)


If you know what to do to stay safe, thunderstorms are a fascinatingly beautiful phenomenon of nature that does not only look amazing on a map. It is part of summer, so keep calm and carry on!

The content on this page has been created by Benjamin D. Hennig. You are free to use the material under Creative Commons conditions (CC BY-NC-ND 3.0); please contact me for further details. I also appreciate a message if you used my maps somewhere else. High resolution and customized maps are available on request.