An unseasonably wet and warm November

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2nd December 2022 – (Hong Kong) With the northeast monsoon over southern China generally weaker than normal for most of the time in the month, November 2022 was much warmer than usual in Hong Kong. The mean minimum temperature of 22.0 degrees and mean temperature of 23.4 degrees were 1.7 degrees and 1.2 degrees above the respective normals and were respectively the second and the third highest for November on record. Together with the exceptionally hot weather in September 2022, Hong Kong experienced the warmest autumn on record from September to November 2022. The mean maximum temperature of 29.2 degrees and the mean temperature of 26.4 degrees for September to November 2022 were both the highest on record for the same period. Moreover, the mean minimum temperature of 24.4 degrees was also one of the highest on record for the same period. Given the rainfall associated with tropical cyclone Nalgae in early November, the month was also much wetter than usual. The monthly total rainfall was 130.8 millimetres, more than three times the normal figure of 39.3 millimetres. The accumulated rainfall up to November this year was 2 179.7 millimetres, a deficit of around 9 per cent compared with the normal of 2 402.4 millimetres for the same period. The month was also unseasonably gloomy with only 100.3 hours of bright sunshine, about 42 per cent below the normal figure of 172.3 hours and the lowest for November on record.
 
 Severe Tropical Storm Nalgae over the northern part of the South China Sea moved generally north-northwestwards towards the coast of Guangdong on November 1. It continued to edge closer to the coast of Guangdong on 2nd November, but weakened into a tropical storm in the afternoon due to the influence of the northeast monsoon. Nalgae skirted past the southern waters of Hong Kong on the night of 2nd November and came closest to the south-southwest of Hong Kong on the early morning of 3rd November. It then weakened into a tropical depression and made landfall over Zhuhai. Nalgae further degenerated into an area of low pressure over the western part of Guangdong in that morning.
 
 Under the combined effect of the northeast monsoon and Nalgae, it was windy with a few showers in Hong Kong on November 1. With the approach of Nalgae, the Observatory issued the No. 8 Gale or Storm Signal on the afternoon of 2nd November. Nalgae was the third tropical cyclone requiring the issuance of the No. 8 Signal in Hong Kong in November since records began in 1946. The last No. 8 Signal in November was in 1972. Strong to gale force winds generally affected the territory with occasional storm force winds offshore and on high ground later on 2nd November and at first on 3rd November. With Nalgae departing from Hong Kong and degenerating into an area of low pressure over the western part of Guangdong, local winds moderated during the day on 3rd November. The outer rainbands of Nalgae brought occasional squally showers to Hong Kong on 2nd and 3rd November. More than 30 millimetres of rainfall were generally recorded over Hong Kong on these two days and rainfall even exceeded 80 millimetres over the urban areas and the eastern part of the territory.
 
Under the influence of a fresh to strong northeast monsoon and with a broad band of clouds covering the coast of Guangdong, local weather was mainly cloudy with a few showers from 4th to 8th November. The showers were particularly heavy on the morning of 8th November. More than 40 millimetres were recorded over Yuen Long. With the thinning out of the cloud band and strengthening of the anticyclone aloft, apart from the cloudier weather on 12th November, the weather of Hong Kong was generally fine from 9th to 13th November. The visibility was also rather low in some areas on 13th November. 
 
 With the prevalence of a fresh to strong northeast monsoon, it was mainly cloudy with sunny periods during the day in Hong Kong from 14th to 17th November. Affected by an anticyclone aloft, the weather turned generally fine again from 18th to 20th November. Under the influence of a fresh to strong northeast monsoon and upper-air disturbances, the weather of Hong Kong turned cloudy with a few rain patches from 21st to 23rd November. With a broad band of clouds covering the coast of Guangdong, local weather remained cloudy with some rain from 24th to 27th November. The visibility was also relatively low in some areas on 27th November. 
 
Affected by an anticyclone aloft, apart from some mist and rain patches, local weather turned generally fine and hot during the day on 28th November. The maximum temperature at the Observatory rose to 28.6 degrees on the afternoon of 28th November, the highest of the month. While the weather remained generally fine and hot during the day on 29th November, there were some fog patches over the eastern waters in the morning with the visibility once falling below 1,000 metres. Meanwhile, the cold front over central China edged south towards southern China and moved across the coast of Guangdong on the morning of 30th November. Under the influence of the associated intense northeast monsoon, local weather became mainly cloudy, windy and cooler on that day. The temperature at the Observatory dropped progressively after noon to a minimum of 18.3 degrees that night, the lowest of the month.
 
Three tropical cyclones occurred over the South China Sea and the western North Pacific in November 2022.
 

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