By Angela Libal
Updated Mar 24, 2022
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Sun halos, often mistaken for mystical phenomena, are a natural consequence of cirrus clouds—thin, high‑altitude formations that develop above 30,000 feet. When water vapor condenses around microscopic mineral particles and freezes, the resulting ice crystals refract and reflect sunlight, creating a luminous ring that surrounds the sun or moon.
Although they frequently appear in clear skies, cirrus clouds are a herald of distant or approaching weather fronts. Warm air below lifts moist, mineral‑laden air upward, where it freezes in the upper troposphere. The presence of a halo typically indicates that a storm system is forming elsewhere and could reach your region within a few days.
Halos can be mesmerizing, but staring at the sun—even for a few seconds—can cause permanent retinal damage. Symptoms may not manifest until several hours after exposure, so it is safest to avoid looking directly at the sun under any circumstances.
