Agreement No. CE 45/2008 (CE) Liantang/Heung Yuen Wai Boundary Control Point and Associated Works 4th Quarterly Environmental Monitoring and Audit Summary Report –
Weather Condition Extracted from HKO
The weather of May 2014
May 2014 was characterized by gloomy and rainy conditions during the first part of the month and persistent hot weather in the latter part. The total rainfall of 687.3 millimetres was more than double the normal amount for May and the seventh highest May rainfall on record. The accumulated rainfall since 1 January of 1066.8 millimetres was about 67 percent above the normal figure of 640.7 millimetres for the same period. With about three quarters of the sunshine occurring in the second half of the month, the total duration of bright sunshine of the month was 107.8 hours, about 23 percent below the normal figure of 140.4 hours. Sunny and hot weather in the last week of the month also brought the average temperature for the month up to 26.4 degrees, half a degree above the normal figure of 25.9 degrees.
The weather in the early part of the month was dominated by late-season northeast monsoon. With a cloud band covering Guangdong and the northern part of the South China Sea, it was cloudy with a few showers in Hong Kong on 1 May. The clouds thinned out gradually and there were sunny periods in the next two days. A trough of low pressure over southern China edged towards the coast on 4 May, moving across the coastal areas of Guangdong the next morning and bringing thunderstorms and heavy showers to the territory. More than 30 millimetres of rainfall were recorded on 5 May over widespread areas in Hong Kong, and rainfall over Sha Tin, Tai Po, Tsuen Wan and Yuen Long even exceeded 50 millimetres. Rain patches continued to affect Hong Kong in the next couple of days. With replenishment of cooler air brought by the northeast monsoon, temperatures at the Hong Kong Observatory fell to a minimum of 18.8 degrees on the morning of 6 May, the lowest of the month.
With the monthly mean temperature reaching 29.0 degrees, June 2014 was the hottest June in Hong Kong since records began in 1884. The monthly mean minimum temperature of 27.0 degrees and maximum temperature of 31.5 degrees were respectively one of the second and the third highest for June. Such high temperatures were attained despite the facts that sunshine duration and rainfall for the month were not far from normal. The total rainfall of the month was 436.6 millimetres, about 4 percent below the normal figures of
456.1 millimetres. The accumulated rainfall since 1 January of 1503.4 millimetres was about 37 percent above the normal figure of 1096.9 millimetres for the same period.
Under the dominance of an anticyclone aloft, the weather in Hong Kong was mainly fine and very hot for the first two days of the month. Affected by a trough of low pressure, it turned cloudy with some showers and isolated thunderstorms on 3 June. With the trough of low pressure pushed back towards the mainland areas of Guangdong, fine and hot weather returned on 4 June apart from a few morning showers. However, the lingering presence of the trough continued to bring a mixture of sunshine and thundery showers to the territory in the next four days.
Under the dominance of a subtropical ridge over southern China for most part of the month, and with episodes of continental air flow brought by passages of tropical cyclones over the East China Sea, July 2014 emerged as the hottest July in Hong Kong with a record-breaking monthly mean temperature of 29.8 degrees. The monthly mean minimum temperature of 27.6 degrees equalled the July record, while the monthly mean maximum temperature of 32.6 degrees also ranked as one of the second highest for July. The month was relatively sunny and drier than usual with a monthly rainfall amount of 260.5 millimetres, about 31 percent below the July normal of 376.5 millimetres. The accumulated rainfall since 1 January was 1763.9 millimetres, about 20 percent above the normal of 1473.3 millimetres for the same period.
The weather started off with mainly cloudy weather and isolated thundery showers in Hong Kong. As a moderate southwest monsoon prevailed over the south China coast, the weather was a mixture of sunshine and showers up to 16 July. On days with more sunshine, daytime conditions became very hot with temperatures exceeding 33 degrees.
Remark: The meteorological data during the Reporting Period is presented in the relevant monthly EM&A report.
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