Social media users shared videos and images of rainbow-coloured clouds appearing over parts of Bekasi and Bogor Regencies, West Java, on Friday, 1 May 2026. The phenomenon drew public attention after several posts circulated widely, including a video uploaded on TikTok.
One widely shared video showed the sky above Jonggol, Bogor Regency, displaying clouds with colours resembling a rainbow. The footage was recorded by a motorist travelling along Jalan Jeprah. The sky appeared mostly clear in the recording, with patches of coloured light visible across the clouds.
The phenomenon prompted questions from the public regarding its cause and whether it was linked to unusual weather conditions.
BMKG Explains Atmospheric Optics Phenomenon
The Meteorology, Climatology, and Geophysics Agency responded to the viral posts by confirming that the phenomenon is related to atmospheric optics. Ida Pramuwardani, Acting Director of Public Meteorology at BMKG, addressed the matter in an official statement on Saturday, 2 May 2026.
“The phenomenon seen in the video is a common occurrence in the atmosphere and is related to atmospheric optics,” she said.
Ida explained that the colours appeared due to the interaction between sunlight and water droplets in the atmosphere. These droplets may originate from residual rain or precipitation occurring in nearby areas. In this case, rainfall was reported in other parts of the Sentul area at the time the video was recorded.
She added that cloud formation also played a role in shaping the visual appearance of the phenomenon.
Not a Sign of Extreme Weather
According to BMKG, the presence of towering cumulus clouds contributed to the incomplete appearance of the rainbow colours. Parts of the clouds partially obscured the light, preventing a full rainbow from forming.
Ida stressed that the phenomenon does not indicate extreme weather conditions. Instead, it reflects normal atmospheric processes under specific conditions.
“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,” she said.
BMKG stated that such optical effects can occur when sunlight is refracted, reflected, and dispersed by water droplets in the air. The agency advised the public not to associate the appearance of rainbow-coloured clouds with hazardous weather events without further meteorological information.