Bulletin updated at 23:20 HKT 21/Sep/2025
9-Day Weather Forecast General Situation: Tropical Cyclone Ragasa will move across the vicinity of Luzon Strait and enter the northern part of the South China Sea in the next couple of days. Under the influence of its outer subsiding air, the weather will be very hot over the coast of Guangdong on Monday to early Tuesday. Ragasa is expected to edge closer to the coast of Guangdong gradually on Tuesday. Under the influence of its broad circulation, the weather over the region will begin to deteriorate rapidly with winds strengthening significantly later on Tuesday. There will be heavy squally showers, thunderstorms and significant storm surge on Wednesday. Seas will be very high with swells. With the departure of Ragasa, showers will ease off gradually in the latter part of this week. Besides, a broad trough of low pressure will bring unsettled weather to the central and northern parts of the South China Sea to the eastern part of the Philippines in the latter part of this week. Date/Month 22/9 (Monday) Wind: East force 4, occasionally force 5 offshore and on high ground, becoming north. Weather: Becoming fine. Very hot during the day. There will be swells. Temp Range: 26 - 34 C R.H. Range: 55 - 95 Per Cent PSR: Low Date/Month 23/9(Tuesday) Wind: North force 5 to 6, force 7 to 8 later, up to force 9 offshore and on high ground. Weather: Becoming cloudy. Very hot with sunny intervals in the morning. Squally showers and thunderstorms later. Seas will be very rough with swells. Temp Range: 27 - 33 C R.H. Range: 55 - 95 Per Cent PSR: Medium High Date/Month 24/9(Wednesday) Wind: East to northeast force 9 to 10. It may reach force 12 offshore and on high ground. Becoming southeast. Force 7 to 8 later. Weather: Cloudy to overcast with heavy squally showers and thunderstorms. Seas will be very high with swells. Temp Range: 25 - 28 C R.H. Range: 80 - 95 Per Cent PSR: High Date/Month 25/9(Thursday) Wind: East to southeast force 5 to 6, force 7 offshore and on high ground at first. Weather: Cloudy with squally showers and thunderstorms. Showers will be heavy at first. Seas will be very rough with swells. Temp Range: 25 - 29 C R.H. Range: 80 - 95 Per Cent PSR: High Date/Month 26/9(Friday) Wind: East force 4, occasionally force 5. Weather: Mainly cloudy with occasional showers and a few squally thunderstorms. Temp Range: 26 - 30 C R.H. Range: 75 - 95 Per Cent PSR: Medium High Date/Month 27/9(Saturday) Wind: East to northeast force 4, occasionally force 5. Weather: Mainly cloudy with one or two showers. Sunny periods during the day. Temp Range: 27 - 32 C R.H. Range: 65 - 90 Per Cent PSR: Medium Low Date/Month 28/9(Sunday) Wind: East force 4 to 5. Weather: Mainly cloudy with a few showers. Temp Range: 27 - 31 C R.H. Range: 65 - 90 Per Cent PSR: Medium Low Date/Month 29/9(Monday) Wind: East to southeast force 4, occasionally force 5. Weather: Mainly cloudy with a few showers and thunderstorms. Temp Range: 27 - 31 C R.H. Range: 70 - 95 Per Cent PSR: Medium Date/Month 30/9(Tuesday) Wind: East to southeast force 4. Weather: Mainly cloudy with a few showers. Temp Range: 27 - 31 C R.H. Range: 70 - 95 Per Cent PSR: Medium Low Sea surface temperature at 2 p.m.21/9/2025 at North Point was 27 degrees C. Soil temperatures at 7 a.m.21/9/2025 at the Hong Kong Observatory: 0.5 M below surface was 29.1 degrees C. 1.0 M below surface was 30.2 degrees C. Weather Cartoons for 9-day weather forecast Day 1 cartoon no. 90 - Hot Day 2 cartoon no. 54 - Sunny Intervals with Showers Day 3 cartoon no. 64 - Heavy Rain Day 4 cartoon no. 64 - Heavy Rain Day 5 cartoon no. 63 - Rain Day 6 cartoon no. 53 - Sunny Periods with A Few Showers Day 7 cartoon no. 62 - Light Rain Day 8 cartoon no. 62 - Light Rain Day 9 cartoon no. 62 - Light Rain