A ferocious rainstorm has brought Hong Kong to a near standstill, prompting the city to issue its highest “black” rainstorm wa ing. Torrential downpours tu ed iconic staircases into waterfalls and forced the closure of schools, courts, clinics, and portions of hospitals. Over 10,000 lightning strikes were recorded in just one hour as up to 90mm of rain per hour soaked the city and its surrounding tech hubs in Guangdong.

Hong Kong Observatory issued a black rainstorm signal for the second time in six hours on Tuesday, August 5, 2025, as torrential downpours lashed the city, disrupting public services and forcing authorities to suspend classes. The highest-level rainstorm warning was first raised at 11.45pm on Monday and again at 5.50am on Tuesday.

As per the forecaster’s records, Tuesday’s black rainstorm warning was the second-longest in Hong Kong’s history, lasting 11 hours and 15 minutes, from 5.50am to 5.05pm.Heavy rains brought parts of the financial hub to a standstill on Tuesday, prompting the suspension of school classes and the opening of temporary shelters. Some hospital services were also affected.So far, 101 flights have been delayed and two have been cancelled as reported by South China Morning Post.

The Hong Kong Observatory warned of the potential for “severe flooding”, stating that “hourly rainfall had already exceeded or was expected to exceed 100 millimetres in some regions”. The black signal indicates rainfall exceeding 70 millimetres in an hour. Images circulating on social media showed cars nearly submerged at an outdoor parking lot in the eastern district of Tseung Kwan O.

Local media reported that public transport had slowed significantly in certain areas, and some subway station exits had been closed. Health authorities confirmed that emergency room services at Queen Mary Hospital were affected due to “severe flooding” on surrounding roads.