- The Great Smog of London, or Great Smog of 1952 sometimes called the Big Smoke, was a severe air-pollution event that affected the British capital of London in December 1952.
- A period of cold weather, combined with an anticyclone and windless conditions, collected airborne pollutants – mostly arising from the use of coal – to form a thick layer of smog over the city.
- It lasted from 5 December to 9 December 1952 and then dispersed quickly when the weather changed.
- Why in news? Doctors compared air pollution in Delhi to Great Smog of London.