The city’s meteorological service has been wrestling with a series of rapid-changing weather patterns across the first week of October. An amber rainstorm warning was activated on the evening of 4 October, signalling the potential for intense rain, strong gusts, and localized flooding. Residents were urged to stay cautious, especially in low-lying districts where drainage is poor.
By the following morning, the warning had been rescinded, yet the atmosphere remained unsettled as lingering showers continued to drench parts of the territory. The evolving situation illustrates how upper-air disturbances over the Pearl River Estuary can trigger abrupt weather spikes in hong kong.
Amber rainstorm warning issued on 4 October
At 8:20 pm on 4 October, the Hong Kong Observatory’s forecaster raised an amber rainstorm warning that was set to stay in force until 10 pm that night. A spokesperson described the outlook as “a few squally thunderstorms” expected to move across the region, with evening showers becoming heavy at times. The warning also highlighted the possibility of intense gusts reaching 70 km/h a level capable of disrupting outdoor activities and creating hazardous driving conditions.
Authorities warned that the combination of heavy rain and strong winds could cause flooding in poorly drained or low-lying neighborhoods. The advisory emphasised vigilance for residents near rivers and coastal inlets, where rapid water accumulation is most likely.
Localised heavy-rain advisory on 2 October
Two days earlier, on 2 October, the Observatory had already placed a localised heavy-rain advisory over the North District of the New Territories. Hourly rainfall totals surpassed 70 mm in several spots, driven by showers and thunderstorms linked to upper-air disturbances. The advisory stressed a serious flooding risk, urging people in flood-prone zones to adopt precautionary measures.
The weather pattern was reinforced by a northeast monsoon affecting Guangdong’s coast, which sustained periods of rain and occasional squalls. Forecasts for the night and the next day called for mainly cloudy skies with intermittent showers, some of which could be heavy. Temperatures were expected to hover between 27 °C and 31 °C accompanied by moderate easterly winds. Drivers were reminded to watch for water-slicked roads and reduced visibility, while the broader outlook hinted at a gradual improvement toward fine and dry conditions by mid-week.
Warning cancelled on 3 October and short-term outlook
By the morning of 3 October, the amber rainstorm warning, along with a concurrent thunderstorm warning, was lifted at 10:46 am. Nevertheless, the city continued to experience widespread downpours, with locations such as Sai Kung and Lantau Island recording more than 70 mm of rain. The Observatory logged a temperature of 26 °C and a relative humidity of 93 % while the ultraviolet index at King’s Park averaged a low 0.2 indicating minimal sun exposure.
Even after the cancellation, officials warned of possible river flooding, given the lingering moisture and the persistent northeast monsoon. Forecasts for the following day predicted a few showers with northerly winds strengthening at night. Morning lows were set to dip to around 24 °C providing a slight cool-down before conditions are expected to become fine and dry by the middle of the next week.
