Unusually warm and dry weather in Hong Kong in March 2024

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3rd April 2024 – (Hong Kong) March 2024 saw an unexpected departure from the typical weather patterns in Hong Kong, with warmer temperatures and drier conditions prevailing throughout the month. Despite the cold weather experienced in early March due to a weakened northeast monsoon, the overall temperature for the month was significantly higher than usual. The monthly mean maximum temperature of 23.9 degrees, monthly mean temperature of 21.1 degrees, and monthly mean minimum temperature of 19.1 degrees surpassed their normal averages by 2.0 degrees, 1.6 degrees, and 1.5 degrees, respectively. These figures ranked among the top records for March, with the maximum temperature peaking at a record-breaking 31.5 degrees on 24th March, surpassing the previous March record set in 1973. Additionally, the month witnessed below-average rainfall, with only 21.6 millimetres recorded, accounting for approximately 29 per cent of the expected 75.3 millimetres.

The weather patterns in early March were characterised by cold temperatures and cloudy skies, accompanied by intermittent rain patches. However, conditions gradually improved, with brighter weather prevailing by the afternoon of 3rd March. A humid southerly airstream brought about misty and cloudy weather with occasional rain patches and rising temperatures on 4th and 5th March. Visibility in the harbour fell to around 1,000 meters on the morning of 5th March. The arrival of the northeast monsoon and extensive cloud cover over Guangdong resulted in cooler temperatures and sporadic rain patches on 6th and 7th March. Weather conditions improved on 8th March, with sunny periods observed during the day.

The influence of the northeast monsoon and cloud cover from Guangdong led to cloudy and cooler conditions with intermittent rain patches on March 9 and 10. Upper-air disturbances caused cloudiness and showers on 11th March, with rainfall exceeding 10 millimetres in many areas. However, weather conditions improved on the night of 11th March, becoming mainly fine the next day. The following two days remained mostly cloudy in Hong Kong.

A transition from the easterly airstream to a humid maritime airstream brought misty conditions and light rain patches on March 16. March 17 and 18 witnessed mainly cloudy and foggy weather with intermittent rain patches. On March 19, a cold front passed through the coastal areas of Guangdong, resulting in morning cloudiness and sporadic rain patches. However, the associated dry northeast monsoon brought about mainly fine and dry conditions in Hong Kong for the remainder of the day and the following two days.

As the northeast monsoon gave way to a warm and humid southerly airstream, 22nd March began with morning cloudiness and occasional rain patches, followed by sunny periods and rising temperatures during the day. The influence of the southerly airstream led to hot weather with ample sunshine from 23rd to 26th March. On 24th March, the temperature at the Observatory skyrocketed to a record-breaking 31.5 degrees, marking the highest maximum temperature ever recorded in March. The mornings of 24th to 26th March also experienced low visibility in parts of the territory. A fresh easterly airstream caused cooler and cloudier conditions with light rain patches on 27th March. The last four days of the month saw mainly cloudy weather with intermittent showers and a subsequent recovery in temperatures due to light wind conditions and a southerly airstream. 29th to 31st March were particularly hot, with the daily mean temperature of 27.1 degrees and daily minimum temperature of 26.0 degrees setting new records for March. Low visibility was also observed on the mornings of 29th and 30th March. Notably, there were no tropical cyclones reported in the South China Sea or the western North Pacific throughout March 2024.