EXTRACT OF METEOROLOGICAL OBSERVATIONS FOR HONG KONG, APRIL 2009
EXTRACT OF METEOROLOGICAL OBSERVATIONS FOR HONG KONG,
APRIL 2009 (Table 1)
| Date APRIL |
Mean Pressure (hPa) |
Air Temperature |
Mean Dew Point Temperature (deg. C) |
Mean Relative Humidity (%) |
Mean Amount of Cloud (%) |
Total Rainfall (mm) |
||
|---|---|---|---|---|---|---|---|---|
|
Maximum (deg. C) |
Mean (deg. C) |
Minimum (deg. C) |
||||||
| 1 | 1019.9 | 22.8 | 19.9 | 18.2 | 13.6 | 67 | 83 | - |
| 2 | 1019.9 | 21.4 | 18.4 | 17.3 | 12.7 | 70 | 85 | Trace |
| 3 | 1017.8 | 20.5 | 18.8 | 16.8 | 14.9 | 78 | 88 | Trace |
| 4 | 1016.4 | 25.0 | 21.5 | 19.7 | 17.6 | 79 | 85 | Trace |
| 5 | 1014.6 | 26.5 | 23.5 | 21.4 | 19.5 | 79 | 82 | - |
| 6 | 1015.9 | 21.4 | 19.1 | 17.2 | 15.9 | 82 | 88 | 8.1 |
| 7 | 1016.5 | 19.8 | 18.2 | 16.9 | 12.7 | 70 | 88 | 0.6 |
| 8 | 1016.5 | 24.8 | 20.8 | 18.2 | 16.1 | 75 | 84 | - |
| 9 | 1016.9 | 24.5 | 20.9 | 19.2 | 11.4 | 55 | 76 | - |
| 10 | 1016.0 | 23.7 | 20.9 | 19.3 | 12.9 | 61 | 74 | - |
| 11 | 1014.7 | 24.7 | 21.5 | 19.7 | 17.2 | 77 | 73 | - |
| 12 | 1011.9 | 24.4 | 21.9 | 20.7 | 19.0 | 84 | 88 | Trace |
| 13 | 1007.9 | 28.4 | 23.7 | 21.6 | 20.8 | 84 | 77 | 5.0 |
| 14 | 1007.9 | 28.6 | 24.7 | 21.9 | 21.1 | 80 | 45 | - |
| 15 | 1009.6 | 25.6 | 23.1 | 21.9 | 19.9 | 83 | 86 | 4.3 |
| 16 | 1005.4 | 25.9 | 23.1 | 21.3 | 20.9 | 88 | 72 | 2.9 |
| 17 | 1007.2 | 28.1 | 23.9 | 21.8 | 20.2 | 80 | 64 | - |
| 18 | 1009.6 | 23.2 | 21.9 | 21.1 | 19.4 | 86 | 86 | 34.1 |
| 19 | 1004.8 | 27.7 | 25.5 | 21.8 | 24.0 | 92 | 92 | 4.5 |
| 20 | 1003.2 | 30.1 | 27.2 | 25.6 | 22.1 | 75 | 70 | - |
| 21 | 1006.7 | 29.3 | 25.3 | 22.2 | 17.8 | 64 | 75 | 1.5 |
| 22 | 1009.6 | 23.9 | 22.4 | 20.9 | 17.9 | 76 | 88 | Trace |
| 23 | 1010.6 | 23.4 | 22.2 | 20.9 | 19.7 | 86 | 94 | 0.2 |
| 24 | 1009.5 | 24.5 | 22.8 | 21.7 | 21.0 | 89 | 89 | Trace |
| 25 | 1010.8 | 24.1 | 22.8 | 19.9 | 21.8 | 94 | 91 | 43.0 |
| 26 | 1015.5 | 19.9 | 19.2 | 18.6 | 17.9 | 92 | 88 | 4.5 |
| 27 | 1015.7 | 24.4 | 21.0 | 19.0 | 15.3 | 71 | 84 | - |
| 28 | 1016.7 | 25.8 | 21.9 | 20.0 | 13.5 | 60 | 36 | - |
| 29 | 1016.5 | 25.4 | 21.9 | 19.8 | 15.9 | 69 | 70 | - |
| 30 | 1015.9 | 26.2 | 22.7 | 20.9 | 16.5 | 68 | 68 | Trace |
| Mean/Total | 1012.7 | 24.8 | 22.0 | 20.2 | 17.6 | 77 | 79 | 108.7 |
| Normal* | 1012.8 | 25.1 | 22.5 | 20.6 | 19.4 | 83 | 80 | 188.5 |
| Station | Hong Kong Observatory | |||||||
EXTRACT OF METEOROLOGICAL OBSERVATIONS FOR HONG KONG,
APRIL 2009 (Table 2)
| Date APRIL |
Number of hours of Reduced Visibility# (hours) |
Total Bright Sunshine (hours) |
Daily Global Solar Radiation (MJ/m2) |
Total Evaporation (mm) |
Prevailing Wind Direction (degrees) |
Mean Wind Speed (km/h) |
|---|---|---|---|---|---|---|
| 1 | 15 | 4.6 | 15.48 | 3.9 | 070 | 40.8 |
| 2 | 19 | 2.1 | 13.29 | 4.0 | 080 | 51.3 |
| 3 | 7 | - | 9.10 | 1.9 | 070 | 38.8 |
| 4 | 2 | 2.6 | 13.69 | 2.3 | 070 | 25.3 |
| 5 | 9 | 6.2 | 17.61 | 4.0 | 020 | 11.9 |
| 6 | 0 | 0.7 | 7.37 | 2.4 | 070 | 28.8 |
| 7 | 2 | - | 5.10 | 1.5 | 070 | 27.3 |
| 8 | 10 | 6.9 | 19.27 | 5.2 | 070 | 23.8 |
| 9 | 0 | 7.0 | 19.77 | 5.1 | 080 | 41.3 |
| 10 | 0 | 3.1 | 13.68 | 3.1 | 080 | 35.0 |
| 11 | 2 | 8.7 | 21.36 | 4.0 | 070 | 26.8 |
| 12 | 8 | 1.7 | 11.90 | 1.8 | 080 | 19.0 |
| 13 | 4 | 4.8 | 15.52 | 2.8 | 010 | 7.5 |
| 14 | 9 | 9.5 | 18.76 | 4.1 | 110 | 4.9 |
| 15 | 6 | 3.7 | 15.10 | 2.6 | 080 | 28.5 |
| 16 | 2 | 5.0 | 15.48 | 3.0 | 060 | 16.2 |
| 17 | 10 | 9.9 | 22.88 | 5.7 | 080 | 24.3 |
| 18 | 0 | 0.5 | 4.80 | 2.0 | 080 | 37.9 |
| 19 | 0 | 0.2 | 3.23 | 0.3 | 160 | 31.3 |
| 20 | 1 | 8.1 | 19.04 | 6.0 | 230 | 11.5 |
| 21 | 1 | 4.6 | 15.91 | 5.8 | 070 | 29.8 |
| 22 | 4 | 0.1 | 9.05 | 2.6 | 070 | 42.0 |
| 23 | 15 | - | 6.05 | 0.8 | 070 | 34.1 |
| 24 | 7 | 0.2 | 8.89 | 2.3 | 030 | 22.5 |
| 25 | 0 | 0.2 | 3.85 | 1.3 | 010 | 18.0 |
| 26 | 6 | - | 1.81 | 1.6 | 070 | 36.4 |
| 27 | 9 | 2.9 | 16.81 | 5.1 | 080 | 37.0 |
| 28 | 0 | 9.9 | 24.88 | 5.9 | 080 | 41.8 |
| 29 | 0 | 8.4 | 19.50 | 3.9 | 080 | 36.5 |
| 30 | 0 | 7.7 | 19.75 | 5.1 | 080 | 38.3 |
| Mean/Total | 148 | 119.3 | 13.63 | 100.1 | 070 | 28.9 |
| Normal* | 95.4§ | 101.8 | 11.83 | 93.2 | 070 | 21.2 |
| Station | Hong Kong International Airport |
King's Park | Waglan Island^ | |||
The minimum pressure recorded at the Hong Kong Observatory was 1001.5 hectopascals at 0241 HKT on 20 April.
The maximum air temperature recorded at the Hong Kong Observatory was 30.1 degrees C at 1202 HKT on 20 April.
The minimum air temperature recorded at the Hong Kong Observatory was 16.8 degrees C at 0157 HKT on 3 April.
The maximum gust peak speed recorded at Waglan Island was 72 kilometres per hour from 080 degrees at 0156 HKT on 2 April.
The maximum instantaneous rate of rainfall recorded at King's Park was 128 millimetres per hour at 1100 HKT on 25 April.
# Reduced visibility refers to visibility below 8 kilometres when there is no fog, mist, or precipitation.
-The visibility readings at the Hong Kong International Airport are based on hourly observations by professional meteorological observers in 2004 and before, and average readings over the 10-minute period before the clock hour of the visibility meter near the middle of the south runway from 2005 onwards. The change of the data source in 2005 is an improvement of the visibility assessment using instrumented observations following the international trend.
-Before 10 October 2007, the number of hours of reduced visibility at the Hong Kong International Airport in 2005 and thereafter displayed in this web page was based on hourly visibility observations by professional meteorological observers. Since 10 October 2007, the data have been revised using the average visibility readings over the 10- minute period before the clock hour, as recorded by the visibility meter near the middle of the south runway.
^ In case the data are not available from Waglan Island, observations of Cheung Chau or other nearby weather stations will be incorporated in computing the Prevailing Wind Direction and Mean Wind Speed.
* 1971-2000 Climatological Normal, unless otherwise specified
§ 1997-2008 Mean value