A rainbow cloud observed in the sky: what is this relatively rare weather phenomenon ?

Un automobiliste a vu et filmé un nuage multicolore en Bretagne (photo d'illustration). Mathias Reding – UNSPLASH

A motorist saw and filmed a multicolored cloud in Brittany, between Rennes and Saint-Malo, this Monday June 3, 2024. This meteorological phenomenon is rather singular.

Have you ever seen a rainbow cloud ? A Breton motorist traveling between Rennes and Saint-Malo was lucky enough to see one this Monday 3& nbsp;June 2024 and capture the scene on his phone, reports Actu Rennes.

Red, orange, yellow, green and cyan blue, beautiful colors transform the classic white cloud into a rainbow cloud. These are cirrus clouds – or clouds – iridescent, specifies Guillaume Séchet, meteorologist interviewed by Actu Rennes.

🌈😍 Un nuage aux couleurs de l’arc-en-ciel a été aperçu dans le ciel de #Rennes par un automobiliste circulant vers St Malo.

⛅️ Un météorologue nous répond sur ce phénomène assez rare !! #Bretagne ⬇️https://t.co/fiVJxFqmhW pic.twitter.com/V7gzEiGxGV

— Actu Rennes (@Rennes24) June 3, 2024

An optical phenomenon

"It’is an optical phenomenon in which the spacing of ice crystals – present in the cloud causes a decomposition of white light. When these small ice crystals, or water droplets, encounter sunlight, the latter disperses, revealing these magnificent colors".

More common at altitude

Iridescence occurs especially in thin clouds. These multi-colored clouds are more common at altitude, and in very humid regions, specifies Futura Sciences . The most spectacular iridescent clouds occur after a shower or thunderstorm, in the late afternoon or early evening, at the end of a hot day.

Ce magnifique nuage lenticulaire irisé a été photographié au Brésil. © Leo Caldas #nuage #clouds #Photographie #lenticular #iridescent pic.twitter.com/kStJCFJRIS

— Cielmania (@cielmania) March 1, 2018

Saturday May 25, 2024, residents of the Pyrénées-Orientales also saw a rainbow cloud in the sky. The phenomenon had been noticed in Collioure, Argelès-sur-Mer, Saint-Cyprien and even Racou.