Parts of the United Kingdom experienced an unusual sight Wednesday morning: a widespread pink fog. The phenomenon, while harmless, prompted weather warnings due to reduced visibility in affected regions.
How Pink Fog Forms
The unusual color isn’t a sign of pollution or a weather hazard; it’s a purely optical effect. Fog is essentially a ground-level cloud composed of tiny water droplets. When sunlight passes through these droplets, especially during sunrise or sunset when the sun is low on the horizon, something interesting happens. The atmosphere scatters shorter wavelengths of light (blues and greens) more effectively than longer wavelengths (reds). This means the remaining light that reaches our eyes is dominated by red hues, giving the fog a distinctly pink appearance.
Affected Areas & Travel Conditions
The Met Office issued a yellow warning for central and northern England, indicating slow-clearing fog until 10:00 AM local time. Particularly dense patches formed in the East Midlands and Cambridgeshire, creating hazardous travel conditions due to poor visibility. Drivers were advised to proceed with caution.
Why It’s Rare
While not unprecedented—similar events were observed in southwest England in 2019—pink fog is uncommon. According to Dr. Claire Ryder of the University of Reading, the right conditions must align perfectly for the effect to occur. This includes temperature drops overnight, clear skies, and the precise angle of sunlight. The color is most visible when the sun is low on the horizon, meaning the phenomenon is limited to early mornings and late evenings.
No Cause For Concern
Despite its surreal appearance, the Met Office emphasizes that pink fog poses no additional risks beyond those associated with regular fog. Reduced visibility remains the primary concern. The physics of light is responsible for the color, not any unusual atmospheric event.
The pink fog serves as a vivid reminder of how common weather phenomena can take on extraordinary forms under specific conditions, offering a unique spectacle without posing a significant threat.
