The onlookers took to Twitter to share the photos of the multi-hued sun halo and expressed their surprise at the unusual sight.
“Remarkable sun halo spotted today from our sports field. The faint coloured rings encircling the sun are formed by the refraction of light through ice crystals in high-level clouds under relatively clear conditions. An uncommon sight in SG,” tweeted the North London Collegiate School.
“What a magnificent day,” marvelled another user on Twitter.
In a comical reference, another user on Twitter remarked, asking if this is the “end of days”.
While another cited if the sight, as per the African mythology, “a sign of great change ahead”.
This is the second time in two years a sun halo was spotted in Singapore skies.
The last such appearance occurred last year in the same month on 22 September. It was spotted at locations such as Tampines, Simei and Ubi at around noon.
What is a sun halo?
Not known to be uncommon, a sun halo is an optical phenomenon that typically occurs amid thin clouds placed high in the sky. Since these thin clouds are made of ice crystals and not of water droplets, they act as tiny prisms. The crystals then refract light in a way that a ring of vibgyor colours appears around the sun.
According to Singapore’s National Environment Agency, it is difficult to forecast precise locations at which these ice crystals are formed in the atmosphere and determine where the halo can appear.
The environment agency also warned that people should not look at the halo with a naked eye as it is dangerous to look at the sun directly without proper protection, reported The Strait Times.