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July 2000 was slightly drier than normal. The total rainfall of 304.0 millimetres was six per cent below normal. However, the accumulated rainfall since January 1 amounted to 1 642.1 millimetres, 25 per cent above the normal figure of 1 316.0 millimetres for the same period.
Two tropical cyclones necessitated the hoisting of the Standby Signal No. 1. The Strong Monsoon Signal was also hoisted on two occasions. The Very Hot Weather Warning was in force for four episodes.
Under the domination of the subtropical ridge of high pressure over the western Pacific, it was mainly fine and very hot on the first day of the month.
Easterly winds affected the south China coastal areas the next few days. Apart from periods of sunshine, there were a few showers and squally thunderstorms on July 2 and 3. Rain eased off on July 4 and it became very hot again under abundant sunshine.
Meanwhile, Kai-tak developed as a tropical depression over the South China Sea west of Luzon. It intensified into a typhoon and drifted slowly towards Taiwan during the next few days. The weather in Hong Kong was hazy with scattered showers and squally thunderstorms in the afternoon and evening. As Kai-tak moved further away, it became fine on July 9 and 10 apart from some showers.
A ridge of high pressure over the Pacific and an area of low pressure near Hainan Island together brought strong southeasterly winds to the territory on July 11. The weather turned mainly cloudy with scattered showers. Weather improved the next day as winds moderated.
Under the influence of a ridge of high pressure over the Pacific, the weather was generally fine on July 13 and 14 apart from one or two isolated showers in the morning.
An area of low pressure over the South China Sea near Xisha intensified into a tropical depression on July 15. Its outer rain bands began to affect Hong Kong in the afternoon, bringing squally showers and occasional strong winds to the offshore waters. It made landfall over Hainan Island the next evening and dissipated quickly.
Following the dissipation of the tropical depression, Hong Kong came under the influence of a strong and active southerly airstream on July 17. Weather deteriorated with heavy squally thunderstorms. Winds subsided on July 18 but heavy rain and thunderstorms continued. Temperatures dropped to a minimum of 24.5 degrees, the lowest in the month. It remained cloudy with squally thunderstorms over the next three days.
A ridge of high pressure over southeastern China brought generally fine weather to the territory on July 22. Sunny and very hot weather prevailed for the next few days. With abundant sunshine, temperatures rose to a maximum of 33.2 degrees on July 28, the highest in the month.
A weak trough of low pressure along south China affected Hong Kong and brought scattered showers and thunderstorms on July 31.
Six tropical cyclones occurred in the South China Sea and the western North Pacific in the month.
Details of the issuance/hoisting and cancellation/lowering of various warnings/signals in the month are summarized in Table 1.1. Monthly meteorological figures and departures from normal of July are tabulated in Table 1.2.
Table 1.1 Warnings and Signals issued in July 2000
Beginning Time Ending Time
Type of Warnings/Signals day/month hour day/month hour
Tropical Cyclone Warning Signals
Name of Tropical Signal
Cyclone Number
Kai-tak 1 6/7 1550 9/7 0545
Tropical Depression 1 15/7 1445 16/7 2125
Strong Monsoon Signal 11/7 1210 12/7 1500
17/7 0300 18/7 0915
Rainstorm Warning Signals
Amber 18/7 0505 18/7 1350
Amber 19/7 1255 19/7 1400
Thunderstorm Warning 2/7 0120 2/7 0620
2/7 1745 2/7 1945
3/7 0730 3/7 0930
3/7 2030 3/7 2130
3/7 2215 4/7 0615
4/7 1815 4/7 1915
5/7 2130 6/7 0030
6/7 0850 6/7 1050
6/7 1430 6/7 1830
7/7 1215 7/7 1315
7/7 1400 7/7 1700
7/7 2120 8/7 0600
8/7 1340 8/7 1740
9/7 0050 9/7 0600
9/7 1520 9/7 1620
10/7 2315 11/7 0515
17/7 0245 17/7 0545
18/7 0245 18/7 1145
18/7 2300 19/7 0600
19/7 1100 19/7 1430
19/7 1915 19/7 2115
20/7 0300 20/7 0600
20/7 0850 20/7 1630
21/7 0650 21/7 1030
21/7 1425 21/7 1730
31/7 2145 1/8 1230
Very Hot Weather Warning 27/6 1630 1/7 1630
4/7 1145 5/7 1635
24/7 1630 27/7 1630
28/7 1335 30/7 1630
Table 1.2 Figures and Departures from Normal - July 2000
Meteorological Element Figure of Departure from normal
the month above normal below normal
Mean Daily Maximum Air 31.3 ---- 0.2
Temperature (Degree Celsius)
Mean Air Temperature 28.8 Normal
(Degree Celsius)
Mean Daily Minimum Air 26.9 0.3 ----
Temperature (Degree Celsius)
Mean Dew Point 24.9 Normal
(Degree Celsius)
Mean Relative Humidity (%) 80 Normal
Mean Cloud Amount (%) 71 6 ----
Total Rainfall (mm) 304.0 ---- 19.5
Total Bright Sunshine 221.9 ---- 9.2
Duration (hours)
Mean Daily Global Solar 17.73 ---- 1.42
Radiation (MJ/Square Metre)
Total Evaporation (mm) 157.6 ---- 14.0
Remarks: All measurements were made at the Hong Kong Observatory except sunshine, solar radiation and evaporation which were recorded at King's Park Meteorological Station.
End/Thursday, August 10, 2000
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