EXTRACT OF METEOROLOGICAL OBSERVATIONS FOR HONG KONG, APRIL 2007
EXTRACT OF METEOROLOGICAL OBSERVATIONS FOR HONG KONG,
APRIL 2007
| 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 | 1009.1 | 27.5 | 25.9 | 24.6 | 21.9 | 79 | 82 | - |
| 2 | 1010.5 | 26.5 | 23.2 | 17.7 | 21.2 | 89 | 88 | 24.2 |
| 3 | 1019.3 | 17.7 | 15.5 | 13.7 | 12.0 | 80 | 88 | 1.6 |
| 4 | 1021.8 | 15.1 | 14.0 | 12.3 | 12.0 | 88 | 93 | 8.9 |
| 5 | 1020.3 | 17.2 | 16.0 | 14.8 | 13.3 | 84 | 88 | Trace |
| 6 | 1018.7 | 20.5 | 18.3 | 16.4 | 15.6 | 84 | 91 | 1.7 |
| 7 | 1017.9 | 20.7 | 18.4 | 16.7 | 15.9 | 86 | 91 | 0.6 |
| 8 | 1018.3 | 21.1 | 19.0 | 17.1 | 15.8 | 82 | 89 | 0.3 |
| 9 | 1018.1 | 23.6 | 20.4 | 18.3 | 14.0 | 68 | 78 | Trace |
| 10 | 1017.7 | 20.2 | 18.5 | 17.2 | 16.0 | 85 | 91 | 6.6 |
| 11 | 1017.2 | 24.0 | 20.3 | 18.0 | 15.2 | 73 | 53 | - |
| 12 | 1016.0 | 24.5 | 20.8 | 18.4 | 13.6 | 65 | 27 | - |
| 13 | 1014.7 | 26.7 | 22.3 | 19.2 | 16.4 | 71 | 77 | - |
| 14 | 1012.3 | 25.7 | 23.1 | 21.0 | 17.8 | 72 | 82 | Trace |
| 15 | 1010.5 | 27.9 | 24.6 | 21.9 | 20.2 | 77 | 69 | - |
| 16 | 1009.8 | 29.4 | 25.8 | 23.6 | 22.0 | 80 | 83 | - |
| 17 | 1009.0 | 27.2 | 25.1 | 20.7 | 21.9 | 83 | 88 | 6.6 |
| 18 | 1013.6 | 28.3 | 22.1 | 17.4 | 11.0 | 53 | 35 | - |
| 19 | 1016.0 | 25.5 | 21.8 | 20.1 | 17.1 | 75 | 51 | - |
| 20 | 1014.4 | 26.4 | 23.0 | 20.7 | 20.1 | 84 | 79 | - |
| 21 | 1012.0 | 25.5 | 24.2 | 23.0 | 22.4 | 89 | 86 | Trace |
| 22 | 1009.7 | 27.9 | 26.0 | 24.0 | 23.2 | 85 | 86 | Trace |
| 23 | 1008.5 | 26.8 | 25.2 | 22.9 | 22.1 | 83 | 88 | 7.8 |
| 24 | 1010.5 | 26.7 | 23.3 | 21.3 | 22.2 | 93 | 89 | 64.4 |
| 25 | 1015.6 | 22.0 | 20.9 | 19.9 | 18.4 | 86 | 86 | 0.6 |
| 26 | 1017.2 | 26.8 | 22.9 | 20.6 | 17.3 | 72 | 43 | - |
| 27 | 1016.5 | 28.2 | 24.0 | 21.5 | 18.2 | 71 | 32 | - |
| 28 | 1015.3 | 26.3 | 23.3 | 22.0 | 19.5 | 79 | 75 | Trace |
| 29 | 1014.4 | 23.0 | 22.5 | 21.5 | 19.9 | 85 | 87 | 0.4 |
| 30 | 1013.6 | 25.2 | 23.3 | 21.7 | 20.9 | 87 | 88 | 1.8 |
| Mean/Total | 1014.6 | 24.5 | 21.8 | 19.6 | 17.9 | 80 | 76 | 125.5 |
| Normal* | 1013.1 | 24.9 | 22.2 | 20.2 | 19.0 | 83 | 78 | 161.5 |
| Station | Hong Kong Observatory | |||||||
| 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 | 0 | 2.7 | 10.54 | 2.7 | 200 | 17.1 |
| 2 | 1 | - | 1.89 | 1.1 | 020 | 22.2 |
| 3 | 0 | - | 1.63 | 1.3 | 010 | 38.0 |
| 4 | 7 | - | 2.25 | 1.3 | 060 | 33.8 |
| 5 | 18 | - | 2.91 | 0.6 | 060 | 26.3 |
| 6 | 6 | - | 5.97 | 0.6 | 020 | 13.8 |
| 7 | 6 | 0.2 | 7.33 | 1.9 | 050 | 20.5 |
| 8 | 13 | 0.3 | 6.84 | 2.0 | 010 | 16.3 |
| 9 | 7 | 8.3 | 21.05 | 4.2 | 090 | 26.2 |
| 10 | 7 | - | 2.25 | 0.9 | 060 | 24.1 |
| 11 | 11 | 9.0 | 21.75 | 4.9 | 090 | 21.1 |
| 12 | 6 | 10.9 | 24.08 | 3.4 | 080 | 22.8 |
| 13 | 7 | 6.9 | 17.83 | 3.7 | 020 | 5.5 |
| 14 | 7 | 2.1 | 12.45 | 2.6 | 230 | 4.1 |
| 15 | 12 | 9.4 | 19.91 | 3.6 | 250 | 13.4 |
| 16 | 4 | 7.8 | 18.70 | 3.8 | 270 | 18.3 |
| 17 | 0 | 0.9 | 7.31 | 4.4 | 150 | 21.9 |
| 18 | 0 | 11.1 | 27.70 | 5.2 | 010 | 24.7 |
| 19 | 0 | 10.0 | 24.49 | 4.6 | 100 | 24.6 |
| 20 | 2 | 6.4 | 19.21 | 3.3 | 080 | 18.0 |
| 21 | 0 | 0.4 | 8.18 | 1.5 | 100 | 12.1 |
| 22 | 0 | 1.0 | 9.82 | 2.8 | 200 | 18.0 |
| 23 | 0 | 0.1 | 4.73 | 5.2 | 210 | 19.3 |
| 24 | 2 | - | 1.76 | 0.3 | 170 | 14.3 |
| 25 | 5 | 0.3 | 4.75 | 3.7 | 020 | 18.8 |
| 26 | 1 | 9.6 | 25.14 | 5.6 | 090 | 26.7 |
| 27 | 7 | 9.6 | 24.61 | 5.5 | 070 | 19.8 |
| 28 | 16 | 5.9 | 19.00 | 3.0 | 080 | 29.5 |
| 29 | 5 | - | 5.52 | 2.0 | 080 | 32.5 |
| 30 | 11 | 0.2 | 8.51 | 1.8 | 070 | 10.2 |
| Mean/Total | 161 | 113.1 | 12.27 | 87.5 | 080 | 20.5 |
| Normal* | 81.2§ | 108.9 | 13.14 | 106.9 | 080 | 19.7 |
| Station | Hong Kong International Airport |
King's Park | Waglan Island^ | |||
The minimum pressure recorded at the Hong Kong Observatory was 1006.0 hectopascals at 1543 HKT on 17 April.
The maximum air temperature recorded at the Hong Kong Observatory was 29.4 degrees C at 1315 HKT on 16 April.
The minimum air temperature recorded at the Hong Kong Observatory was 12.3 degrees C at 0203 HKT on 4 April.
The maximum gust peak speed recorded at Waglan Island was 76 kilometres per hour from 350 degrees at 2100 HKT on 17 April.
The maximum instantaneous rate of rainfall recorded at King's Park was 168 millimetres per hour at 1048 HKT on 24 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.
The calibration factors of the pyranometer at King's Park in 2006 and 2007 have been re-computed based on the results of a regional instrument comparison in Asia in 2007. The readings of total global solar radiation at King's Park in 2006 and 2007 displayed in this web page before 13 June 2008 have been revised on 13 June 2008 using the new calibration factors.
^ 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.
* 1961-1990 Climatological Normal, unless otherwise specified
§ 1997-2006 Mean value