An extremely dry and sunny April
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April 2022 was much sunnier than usual. The total duration of bright sunshine in the month was 191.1 hours, about 69 per cent above the normal figure of 113.2 hours and the fifth highest on record for April. The month was also warmer than usual with a mean temperature of 23.7 degrees, 0.7 degrees above the normal figure of 23.0 degrees.
A cold front moved across the coast of Guangdong in the morning of April 1. Under the influence of the associated northeast monsoon, the weather was cloudy and rather cool with a few rain patches on the first two days of the month. The temperature recorded at the Hong Kong Observatory (HKO) dropped to a minimum of 13.7 degrees on April 2, the lowest of the month. Affected by a dry northeast monsoon, the weather was generally fine from April 3 to 10. It was very dry during the day on April 3, 4 and 8. The relative humidity recorded at the HKO once dropped to 22 per cent on April 8, the lowest on record in April since the automatic weather station was established at the HKO Headquarters in 1984.
Under light wind conditions, local weather was generally fine and hot during the day from April 11 to 12. Affected by an upper-air disturbance, the weather turned mainly cloudy with a few showers in the morning of April 13. The visibility was rather low in some areas and once fell below 1 000 metres at Waglan Island. Under the influence of an anticyclone aloft and the subsequent fresh to strong dry northeast monsoon, sunny and dry weather returned on the next two days.
Under the influence of a strong northeast monsoon, the weather turned mainly cloudy and rather windy from April 16 to 17. Affected by the cloud bands over southern China and the subsequent upper-air disturbance, it was cloudy with a few showers on April 18 and 19. With the moderation of the northeast monsoon and thinning out of the cloud band, local weather gradually became sunnier from April 20 to 21.
Affected by a humid southerly airstream, local weather was mainly cloudy with morning mist on April 22. The weather became hot with sunny periods during the day from April 23 to 27. There was coastal fog in the mornings of April 23 to 25 and April 27. The visibility at Waglan Island once fell to around 200 metres on April 25. Dominated by an anticyclone aloft, apart from coastal fog in the morning of April 29, the weather was generally fine and hot during the day on April 28 and 29. With plenty of sunshine, the temperature recorded at the HKO rose to a maximum of 32.0 degrees in the afternoon of April 29, the highest of the month. Affected by a fresh to strong easterly airstream, the weather turned mainly cloudy with showers on the last day of the month. There was coastal fog that morning.
Two tropical cyclones occurred over the South China Sea and the western North Pacific in April 2022.
Details of issuance and cancellation of various warnings/signals in April are summarised in Table 1. Monthly meteorological figures and departures from normal for April are tabulated in Table 2.
Ends/Wednesday, May 4, 2022
Issued at HKT 15:00
Issued at HKT 15:00
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