9-day Weather Forecast for Hong Kong
General Situation:
Tropical Cyclone Ragasa will edge closer to the vicinity of the Pearl River Estuary to the western coast of Guangdong today. Under its influence, there will be frequent heavy squally showers, thunderstorms and significant storm surge over the coast of Guangdong. Seas will be phenomenal with swells. With the departure of Ragasa, the weather will improve with showers easing off gradually in the latter part of this week. Besides, Tropical Cyclone Bualoi over the western North Pacific will develop gradually today and tomorrow. It will move across the Philippines and enter the South China Sea, with a higher chance of moving towards Hainan Island and the seas south of it subsequently.
24 Sep (Wed) 24 | 27°C 80-95% Northeast force 11 to 12, becoming southeast in the morning. Force 7 at night. Cloudy to overcast with frequent heavy squally showers, thunderstorms and significant storm surge. Seas will be phenomenal with swells. 25 Sep (Thu) 25 | 29°C 80-95% East to southeast force 5 to 6, force 7 offshore and on high ground at first. Cloudy with squally showers and thunderstorms. Showers will be heavy at first. Seas will be very rough with swells. 26 Sep (Fri) 26 | 31°C 70-95% Mainly cloudy with a few showers. Isolated thunderstorms at first. Sunny intervals during the day. 27 Sep (Sat) 28 | 32°C 65-90% Sunny periods and one or two showers. 28 Sep (Sun) 27 | 31°C 70-95% East force 4. Mainly cloudy with a few showers. Sunny intervals during the day. 02 Oct (Thu) 27 | 31°C 70-95% East force 3. Mainly cloudy with a few showers. Sunny intervals during the day. |
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Forecast: maximum temperature
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Forecast: maximum relative humidity
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Updated at: 04:00 HKT 24/Sep/2025
(Next update at: 11:30 HKT 24/Sep/2025)
This link will open in a new windowAutomatic Regional Weather Forecast in Hong Kong & Pearl River Delta Region
Climatological information for 24/Sep/2025-02/Oct/2025
2 pm on 23/Sep/2025 at North Point :
7 am on 23/Sep/2025 at Hong Kong Observatory
- 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:
High>=70% | For every 100 forecasts with a "high" probability, there are about 70 times or more with an average accumulated rainfall of 10 mm or above in actual observation. | |
Medium High 55-69% | For every 100 forecasts with a "medium high" probability, there are about 55 to 69 times with an average accumulated rainfall of 10 mm or above in actual observation. | |
Medium 45-54% | For every 100 forecasts with a "medium" probability, there are about 45 to 54 times with an average accumulated rainfall of 10 mm or above in actual observation. | |
Medium Low 30-44% | For every 100 forecasts with a "medium low" probability, there are about 30 to 44 times with an average accumulated rainfall of 10 mm or above in actual observation. | |
Low<30% | For every 100 forecasts with a "low" probability, there are about less than 30 times with an average accumulated rainfall of 10 mm or above in actual observation. |
- 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.