[CLARIFICATION: A statement issued on Wednesday from the Meteorological Service Singapore has revised the time a hailstorm was last seen to 12 September 2009, based on newspaper reports. Previously, NEA officials said the last time there was a hailstorm in Singapore was 27 March 2008.]
The hailstorm which hit certain parts of western Singapore is not toxic, a National Environment Agency (NEA) spokesman assured in a media conference.
The agency added that hail is caused by supercooled water droplets freezing on contact with particles in the air, such as dust, during a thunderstorm, and PM2.5 and PM10 are only hazardous when inhaled. NEA was unable to confirm if the hailstorm was brought about by the haze.
The last hailstorm in Singapore took place about four years ago, on 12 September 2009, according to newspaper reports.
Residents in western Singapore reported seeing hail falling from the skies at about 3pm on Tuesday.
Heavy rain, accompanied by gusty winds, started around 3pm in areas including Jurong and Bukit Batok – a welcome respite for Singaporeans who only recently endured over a week of record-breaking haze caused by forest fires in Indonesia.
Musician Laura Tang, 24, was near West Coast Park when she noticed the hail.
"The wind suddenly turned very cold, and these crystal-like stones started raining down," she said.
"It was very frightening. I could not believe my eyes," she added.
Ms Caydence Woo, 24, said the substance felt like "very sharp droplets that were a little prickly, like sand, when it landed on my hand".
The banking executive was on her way to Clementi Mall when she noticed the sound of droplets bouncing off her umbrella was exceptionally loud, and decided to put her hand out to feel them.
“The droplets also looked weird. They were coming down in straight, solid lines, instead of one by one,” she said.
[See photos of the hailstorm in our slideshow here]
Marketing manager Edwin Yao, 30, also experienced the hail storm.
He was in a taxi at the Bukit Timah nature reserve area when he noticed “ice” hitting the taxi and the surrounding vehicles. He described the hail to be roughly the size of a 50-cent coin.
This continued for the next five to 10 minutes, he said. He did not notice any damage to vehicles.
Wynfred Wong, a 13-year-old student, also saw a strange sight of “string-like” rain out of her window in Jurong East. She decided to make her way downstairs to get a closer look.
The droplets looked solid when they were coming down, but melted into water the moment she touched them, she said.
The ground where the droplets landed had “a lot of bubbles,” she added.
With reporting by Peace Chiu, Winifred Wong, Justin Ong and Elizabeth Soh.