Deep Red Sun Phenomenon in Medan Causes a Stir, BMKG Explains

The sighting of a red sun caused a stir among residents of Medan. The Meteorology, Climatology and Geophysics Agency (BMKG) has explained that the phenomenon is nothing to worry about.

Quoted by detikSumut on Tuesday (8/9/2026), BMKG Region I revealed that the reddish sun seen over the city of Medan was caused by particles in the atmosphere, such as aerosols, dust or smoke, which affect the propagation of sunlight.

“Particles in the atmosphere, such as aerosols, dust or smoke, affect the way sunlight travels,” according to a statement posted on BMKG North Sumatra’s Instagram account.

BMKG explained that these particles scatter more of the blue light, so the light reaching the eye is dominated by red or orange hues.

“The effect is more visible when the sun is low in the sky, such as in the morning or late afternoon,” it said.

BMKG Region I suspected that the red sun phenomenon at the time was due to the presence of aerosols in the atmosphere. Based on observed atmospheric conditions, hazy weather occurred in Medan and its surroundings from late afternoon into the evening.

“So the red sun seen by residents of Medan yesterday was an atmospheric optical effect. It does not mean the sun has changed colour; rather, the sunlight underwent scattering and filtering by atmospheric conditions before reaching the observer’s eye,” the agency said.