Noctilucent clouds over Margate Harbour and Lighthouse at night June 2021.

Noctilucent clouds, or night shining clouds, are tenuous cloud-like phenomena in the upper atmosphere of Earth. They consist of ice crystals and are only visible during astronomical twilight. Noctilucent roughly means "night shining" in Latin. They are most often observed during the summer months from latitudes between ±50° and ±70°. They are visible only during local summer months and when the Sun is below the observer's horizon, but while these very high clouds are still in sunlight. Recent studies suggest that increased atmospheric methane emissions produce additional water vapor once the methane molecules reach the mesosphere – creating, or reinforcing existing noctilucent clouds.

They are the highest clouds in Earth's atmosphere, located in the mesosphere at altitudes of around 76 to 85 km (249,000 to 279,000 ft). They are too faint to be seen in daylight, and are visible only when illuminated by sunlight from below the horizon while the lower layers of the atmosphere are in Earth's shadow.

The original lighthouse was designed by the architect William Edmunds and was completed in 1829. It was destroyed in the North Sea flood of 1953. The design was a round Doric column similar to the lighthouse at Whitby.

A replacement lighthouse with an octagonal column was built in 1955. This lighthouse features on the series G Bank of England £20 note along with the Turner Contemporary.