The stifling month-long heatwave ended yesterday with a thunderstorm and downpour that finally brought temperatures below 30 degrees Celsius.
The very hot weather warning was cancelled at noon yesterday after being in force for a record 12 days, or 286 hours, since July 24.
There were downpours in a number of areas yesterday and the Observatory issued a thunderstorm warning. And after temperatures of more than 30 degrees Celsius over the past two weeks, the thermometer dropped to around 27 degrees after the rain at noon.
The relief is likely to continue this week with cloudy weather and scattered showers predicted, bringing lower temperatures.
'The heatwave is over,' an Observatory spokesman said, adding that the temperature was forecast to hover between 27 and 31 degrees.
The Observatory said a tropical storm had formed south of Hainan in the South China Sea that was expected to move northwest.
Hong Kong has not been affected by any tropical cyclones this summer.
Despite the cooler weather, a police officer suffered a stroke and collapsed yesterday morning. He was taken to Prince of Wales Hospital and was in stable condition.
The officer was on duty at a vehicle weighing facility in Ma Liu Shui where he was responsible for security tasks relating to the preparation for the Olympic equestrian events.
Several weather records were broken last month. The average maximum temperature was 32.9 degrees, 0.3 degrees higher than the previous record set in 1967. And only about 76.9mm of rain was recorded - a quarter of the usual 323mm.
Experts said the hot weather was the result of an exceptionally strong subtropical ridge of atmospheric air pressure covering large areas of the western Pacific.