There is a ring around the Moon—called a lunar halo —when moonlight passes through millions of tiny ice crystals in thin, high cirrus or cirrostratus clouds in Earth’s upper atmosphere.

Quick Scoop

  • The “ring” is an optical effect, not a physical ring around the Moon.
  • Hexagon‑shaped ice crystals bend (refract) the light at a specific angle, usually creating a halo with a radius of about 22 degrees from the Moon, often called a 22‑degree halo.
  • These ice crystals typically sit 5–10 km high in the atmosphere, where temperatures are well below freezing even when ground weather feels mild.

How the ring forms

  • Moonlight is just reflected sunlight; as it enters one side of an ice crystal and exits another, it is bent, concentrating light into a circle around the Moon rather than evenly across the sky.
  • Because the crystals tend to be hexagonal, the bending angle is similar from crystal to crystal, which is why the ring has a nearly fixed size instead of being random.
  • Everyone effectively sees their “own” halo, because the crystals sending light to one person are not exactly the same ones lighting up the ring for someone a few meters away.

Colors and appearance

  • Many lunar halos look white, but they can show faint color, with a reddish inner edge and bluish outer edge, similar in principle to a very pale rainbow.
  • The Moon often looks hazy or slightly dimmer inside the ring, while the sky beyond the ring can appear darker by contrast.
  • A second, larger and much fainter 44‑degree halo is occasionally visible under special conditions, but the 22‑degree halo is by far the most common.

Weather lore and “latest news”

  • High ice‑crystal clouds that create halos are often associated with an approaching warm front, so a ring around the Moon can sometimes precede rain or snow by a day or two.
  • This is the origin of sayings like “Ring around the Moon, rain or snow soon,” which have a kernel of truth because cirrostratus clouds often arrive before a storm system.
  • Recent explainer pieces and videos still highlight lunar halos as a popular “trending” night‑sky sight, especially when photographed and shared on social platforms after bright full Moons.

Folklore, myths, and reality

  • In older traditions, a halo around the Moon could be read as a sign of coming change, bad weather, or even a spiritual omen, but modern science treats it as a predictable optical phenomenon.
  • Some folk tales claim that counting stars inside the ring tells how many days until bad weather; this is fun but not a reliable forecast method.
  • Astronomers and atmospheric scientists today use lunar halos mainly as visual clues about high‑altitude moisture and ice, not as direct forecasting tools.

TL;DR: A ring around the Moon happens when light passes through high‑altitude ice crystals, bending at a fixed angle to form a 22‑degree halo, often ahead of changing weather.

Information gathered from public forums or data available on the internet and portrayed here.