A lunar halo circles the moon over Pingtan, East China's Fujian province, March 31, 2015. The halo is caused by both refraction (splitting of light) and reflection (glints of light) from ice crystals in the air. [Photo: China News Service/Cai Qihui]

A lunar halo has appeared in the night sky in Pingtan City in southeast China's Fujian Province on March 31, 2015.

A lunar halo is a rare meteorological phenomenon. It happens when moonlight is refracted through ice particles in the earth's atmosphere, as the local meteorological department reported.

The lunar halo with a large diameter in Pingtan was clearly visible.

Witnesses say there was a clear halo around the moon, radiating multiple colors including red, yellow and purple, which makes it looks like a rainbow.

The color of the halo is usually seen as purple in the outer ring and red in the inner ring. But sometimes the halo may also present as a silver circle.

According to folk sayings, the appearance of a lunar halo is an indicator of an imminent weather change of weathers is on the way. The Local meteorological station has forecasted that windy weather will hit Pingtan in the following days.