Fluctuating temperatures in March
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With the northeast monsoon bringing a continental airstream to southern China, the weather in Hong Kong was generally fine and dry on the first four days of the month, with the daytime relative humidity falling below 30 per cent on March 2.
As the northeast monsoon subsided and a maritime airstream set in, the weather turned cloudier on March 5 and a spell of cloudy conditions persisted for the next two weeks. Affected by coastal fog on the morning of March 6, the visibility dropped to around 100 metres at Waglan Island. A replenishment of the northeast monsoon reached the coast of Guangdong later that day and brought cooler weather to Hong Kong over the next two days. More than 10 millimetres of rain was recorded over the northeastern part of the New Territories on March 8. Under the influence of a moist easterly airstream, there were mist and light rain patches in the next four days. There was morning fog on March 13, with visibility falling below 1000 metres in the harbour, and the weather during the daytime was relatively warm with sunny intervals.
After another foggy start on March 14, a cold front crossed the coast of Guangdong later in the morning and brought overcast skies with widespread rain. With strengthening easterly winds, the weather in Hong Kong turned windy with cooler temperatures over the next two days. As the northeast monsoon gradually weakened, a maritime airstream moved towards the coast of Guangdong and there were some light rain patches as well as coastal fog in Hong Kong on March 17 and 18. Affected by an upper-air disturbance, the rain became heavier on March 19 with more than 30 millimetres of rain recorded over the New Territories.
Apart from some mist or fog patches, the weather in Hong Kong turned fine and very warm on March 20 and 21. With abundant sunshine, temperatures at the Hong Kong Observatory climbed to a maximum of 27.6 degrees on March 21, the highest of the month. As a freshening easterly airstream brought a replenishment of the northeast monsoon and cooler weather to the coast of Guangdong the next day, the weather in Hong Kong turned cloudy with some light rain patches. As the monsoon winds subsided, there were sunny periods with some mist on March 23 and 24. A cold front moved across the coast of Guangdong on March 25, bringing cloudy weather and some light rain patches to Hong Kong. Temperatures over the territory fell significantly, and temperatures at the Hong Kong Observatory dropped to a minimum of 13.8 degrees the next morning, the lowest of the month, marking a temperature difference of nearly 14 degrees compared to the maximum temperature recorded at the Observatory five days before.
With a continental air mass spreading to the south China coast, local weather turned mainly fine and dry on March 27. As a maritime airstream returned to the coast of Guangdong, local weather became warmer and more humid with mist patches over the next three days. While it was foggy on the morning of March 31, a cold front moved across the coast of Guangdong during the day, bringing cooler and more rainy weather with a few thunderstorms to the territory.
There was no tropical cyclone over the South China Sea and the western North Pacific in March 2017.
Details of issuance and cancellation of various warnings/signals in March are summarised in Table 1. Monthly meteorological figures and departures from normal for March are tabulated in Table 2.
Ends/Wednesday, April 5, 2017
Issued at HKT 16:38
Issued at HKT 16:38
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