Source: Hong Kong Government special administrative region
Automatic Regional Weather Forecast in Hong Kong & Pearl River Delta RegionClimatological information for {2}-{3}{1} on {0} at {2} :
{3} °C{1} on {0} at {2}
0.5m depth:{3}°C
- This middle 50% range (between 25th and 75th percentiles) is calculated based on the maximum/minimum temperature and relative humidity data within a 5-day period centred on that day in the 30 years from 1991 to 2020.
- “9-day Weather Forecast” provides general indications of the trends in weather for the coming 9 days. For detailed description of today’s weather forecast, please refer to “Local Weather Forecast“.
- The Probability of Significant Rain (PSR) forecast provides users with additional reference on rainfall amount and forecast trend for the coming 9 days. The PSR forecast on each day indicates the probability of the accumulated rainfall generally over Hong Kong reaching 10 mm (i.e. around the mean daily rainfall in rainy season) or more on that day. There are 5 categories of probability as follows:
- The accuracy of forecast generally decreases while the error generally increases with forecast period. For forecast elements in “9-day Weather Forecast” other than PSR, the average accuracy for the next one to three days, four to seven days, and eight to nine days are about 90%, 85% and 80% respectively. The errors of PSR forecast in the next one to six days are within around 10% and those in seven to nine days are within around 20%.
- The accuracy and error of forecast also vary for different weather systems in different seasons. Generally speaking, weather in spring and summer such as fog, tropical cyclone and severe convective weather is more changeable, resulting in higher uncertainty of forecast.