A dry and unseasonably warm November
With the northeast monsoon over the south China coast weaker than normal for most of the time during the month, November 2023 was much warmer than usual in Hong Kong. The monthly mean temperature of 23.5 degrees, monthly mean maximum temperature of 26.1 degrees and monthly mean minimum temperature of 21.6 degrees were 1.3 degrees, 1.6 degrees and 1.3 degrees above their corresponding normals and respectively one of the second, one of the third and one of the fourth highest on record for November. Together with the higher than usual temperatures in September and October, the autumn of this year from September to November was also much warmer than usual. The mean minimum temperature of 24.4 degrees, mean temperature of 26.1 degrees and mean maximum temperature of 28.8 degrees were respectively one of the highest, one of the second and fifth highest on record for the same period. The month was drier than usual with a total rainfall of 3.3 millimetres, only about 8 per cent of the normal figure of 39.3 millimetres. Mainly attributed to record-breaking rainstorms in September and October, the autumn of this year was exceptionally wet with a total rainfall of 1 616.4 millimetres, the highest on record for the same period. The accumulated rainfall this year up to November was 2 773.6 millimetres, about 15 per cent above the normal figure of 2 402.4 millimetres for the same period.
Under the influence of a dry northeast monsoon, the weather of Hong Kong was fine and dry during the day on the first six days of the month. With plenty of sunshine, temperatures at the Observatory rose to a maximum of 30.7 degrees on the afternoon of November 6, the highest of the month. Moreover, the daily mean temperature of 27.6 degrees on that day was the highest on record for November.
With a band of clouds covering the coast of Guangdong and under the influence of a fresh to strong easterly airstream, the weather of Hong Kong turned mainly cloudy and cooler with a few rain patches on November 7 and 8. With the moderation of the easterly airstream, it was brighter and warmer with sunny intervals during the day on November 9 and 10. The daily minimum temperature of 25.6 degrees on November 10 was one of the highest on record for November. A cold front moved across the coast of Guangdong on the morning of November 11. Locally, it was mainly cloudy with a few rain patches on that day. The associated northeast monsoon brought mainly fine and slightly cooler weather to Hong Kong during the next four days.
With the arrival of another replenishment of the northeast monsoon on November 16, local weather was mainly cloudy at first on that day and became mainly fine and dry in the afternoon. It was sunny and very dry with cool mornings on the next two days. The temperature at the Observatory dropped to a minimum of 15.6 degrees on the morning of November 17, the lowest of the month. Under the influence of a dry northeast monsoon and the subsequent replenishment, fine and dry weather prevailed in Hong Kong from November 19 to 28. With a band of clouds covering the coast of Guangdong and under the influence of an easterly airstream, local weather turned cloudier with a few light rain patches on the last two days of November.
There was no tropical cyclone over the South China Sea and the western North Pacific in November 2023.
Details of issuance and cancellation of various warnings/signals in the month are summarised in Table 1. Monthly meteorological figures and departures from normal for November are tabulated in Table 2.