(Bloomberg) -- A week after buildings swayed and the seas swelled under the high winds of super typhoon Saola, Hong Kong faced a new disaster: 600 mm (23.6 inches) of rain in 24 hours, a deluge that flooded roads, triggered landslides and shut down the city for the second time in a week.
Mother Nature couldn't have made it plainer. With climate change, severe storms are happening more often in Hong Kong, as in most places, and they're getting worse.
“Climate change is affecting Hong Kong not only through tropical cyclones and intense rainstorms, but also through extremely hot days and nights,” said Jed Kaplan, a former associate professor with the department of Earth Sciences at the University of Hong Kong, and now on the faculty at University of Calgary.
“All of these meteorological phenomena lead to conditions that can be difficult for people to handle,” he said. “Increased incidences of heatstroke and other heat related illnesses, damage to infrastructure from rain and flooding, hurricane-force winds, and landslides all contribute to economic damage and costly investments in repair and mitigation of future risks.”
Read more: Hong Kong Shuts Down City After Heaviest Rainfall On Record
The Hong Kong Observatory has meteorological data dating to the early decades of British Colonial rule, when fewer than 220,000 people called the city home. Here's what it tells us about how the weather has changed:
The city gets a little more rain each year.
It's been 60 years since Hong Kong last notched record-low annual rainfall. Since then, it’s set a new high at least 13 times.
The record for hourly rainfall strength has been breaking at a much faster pace since 1990, and locals can expect more to come. “The heavy precipitation events will intensify and become more frequent in the future,” a spokesperson for the Hong Kong Observatory said. Over the past 24 hours, the rainfall in the city equaled roughly a quarter of the average annual total, the heaviest since data’s been recorded.
Mean temperatures recorded at the Hong Kong Observatory’s headquarters showed an average rise of 0.28C each decade from 1993 through 2022, double the overall pace since 1885. Earlier this year, the city instituted anti-heatstroke guidelines for employers after the financial hub registered a record 15 days at or above 35C in 2022.
It’s also less cold.
It’s not as obvious as it sounds. Not only is Hong Kong experiencing more very hot days with maximum temperatures of 33C or above, it’s experiencing fewer cold days of minimum 12C or below. It’s also not cooling off as much at night, which amplifies higher daytime temperatures. The past week of wind and rain did little to lower the temperature, which stayed at or above 25C throughout.
In Pictures: ‘Black Friday’ Rainstorm Batters Hong Kong
By late Friday afternoon, the Observatory lifted its rain warning, leaving the landslide caution in place and warning of “extreme conditions” through midnight. After that, the forecast calls for highs around 30 — and more rain.
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