A spectacular rainbow-coloured cloud that lit up the skies above a small Indonesian town has captivated millions online after footage of the dazzling display spread rapidly across TikTok and social media — racking up tens of millions of views and briefly bringing traffic to a standstill.
The phenomenon was spotted above Jonggol in the Bogor Regency of West Java on Friday 1 May, drawing public attention and briefly disrupting traffic as residents stopped their vehicles to record it. The footage was first captured by a motorist travelling along Jalan Jeprah. One local witness, 21-year-old Ahmad Baehaqy Pratama, said: “It hadn’t rained yet, but on the right side it looked like there was a rainbow.”
The Weather Channel shared the viral video — originally posted by Indonesian TikTok user @sipa4502 — which accumulated a combined 57 million views. Within hours, the footage had travelled far beyond Indonesia, drawing reactions from viewers across the world who marvelled at the vivid streaks of colour threading through the clouds in an otherwise clear afternoon sky. Some compared it to the rainbow road from Mario Kart. Others, perhaps less charitably, called it AI.
It was neither. Indonesia’s Meteorology, Climatology and Geophysics Agency, known as BMKG, was quick to explain the science behind the display. Ida Pramuwardani, the agency’s Acting Director of Public Meteorology, confirmed to Detik News that the phenomenon was entirely natural. “The phenomenon seen in the video is a common occurrence in the atmosphere and is related to atmospheric optics,” she said. “Rainbow colours appear because sunlight interacts with water droplets in the air, both from rain residue and rain that is currently occurring on the other side of the Sentul area, as in the video.”
Pramuwardani explained that a towering cumulus cloud was partially obscuring a rainbow forming behind it, creating the distinctive incomplete arc that gave it such an unusual appearance. “At the same time, there are towering cumulus clouds that can cover part of the rainbow, so that the shape looks incomplete or looks like a ‘rainbow cloud’,” she said. Crucially, she stressed the sight was not a warning sign of any impending danger. “This phenomenon is not a direct sign of an impending storm, but rather indicates the growth of convective clouds and the possibility of local rain in the area, even though the observation point is still clear or has not experienced rain.”
The phenomenon is known scientifically as cloud iridescence — caused by the diffraction of sunlight as it passes through tiny water droplets or ice crystals suspended in the atmosphere. Unlike a conventional rainbow, which forms a complete arc on the opposite side of the sky from the sun, iridescent clouds typically appear close to the sun’s position and spread across the edges of thin cloud formations rather than forming a defined curve. While standard iridescent clouds are considered relatively common, the intensity and vividness of the colours seen over Jonggol — bright enough to stop traffic and be filmed clearly in daylight — is considerably rarer.
The scepticism that greeted the footage online is itself telling. In an era of AI-generated imagery and viral misinformation, many viewers defaulted to disbelief, with comments questioning whether the video had been digitally manipulated. Scientists and meteorologists were unequivocal, however — what locals witnessed above Jonggol was nothing more, and nothing less, than sunlight doing what it has always done.
