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EXTRACT OF METEOROLOGICAL OBSERVATIONS FOR HONG KONG, JULY 2009

EXTRACT OF METEOROLOGICAL OBSERVATIONS FOR HONG KONG,
JULY 2009

Date
JULY
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 1008.7 32.6 29.6 28.2 24.3 73 63 -
2 1007.1 31.5 29.6 28.4 24.5 75 74 Trace
3 1005.2 30.8 29.5 28.6 24.7 76 86 0.5
4 1006.1 29.3 28.5 24.9 25.3 83 90 17.4
5 1008.4 27.9 25.8 24.1 24.8 94 88 49.6
6 1010.2 32.0 27.8 23.9 25.2 86 77 31.2
7 1009.4 32.0 29.2 26.3 24.7 77 57 20.1
8 1008.0 32.5 29.5 27.7 24.5 75 35 -
9 1006.5 32.7 29.7 27.9 24.1 72 20 -
10 1003.1 33.1 30.2 27.6 25.1 75 30 Trace
11 1002.0 31.9 28.9 27.6 25.0 80 84 8.1
12 1004.8 33.0 29.6 28.0 25.6 79 60 Trace
13 1004.7 33.0 29.6 27.6 25.0 77 53 -
14 1004.3 31.0 29.2 27.8 25.0 78 72 -
15 1005.2 32.8 29.4 27.5 26.2 83 78 4.8
16 1005.5 32.5 29.2 27.5 26.0 83 72 0.8
17 1002.9 32.5 29.9 27.7 24.4 73 39 0.4
18 997.4 34.3 29.4 26.0 25.1 78 72 11.7
19 999.9 28.7 26.4 25.0 24.5 89 90 124.6
20 1008.6 31.5 28.4 25.7 26.0 87 73 8.1
21 1009.3 32.5 29.0 27.2 25.7 83 62 0.6
22 1006.7 32.4 28.9 27.3 25.1 80 51 -
23 1005.3 32.1 28.9 26.9 25.2 81 67 7.6
24 1004.1 31.0 29.5 27.9 25.4 79 84 2.6
25 1003.9 31.5 29.6 27.5 25.6 80 82 8.3
26 1003.9 33.1 29.1 27.4 26.2 85 86 24.1
27 1003.0 30.8 28.7 25.3 26.0 86 81 33.6
28 1002.4 32.6 29.3 26.6 26.2 84 82 10.2
29 1003.7 33.3 29.9 27.9 26.4 82 78 2.4
30 1003.4 31.5 28.9 27.4 26.6 88 79 14.0
31 1004.1 32.5 29.3 26.9 26.1 83 71 8.7
Mean/Total 1005.1 31.9 29.1 27.0 25.3 81 69 389.4
Normal* 1005.5 31.3 28.7 26.7 25.0 81 68 374.4
Station Hong   Kong   Observatory

Date
JULY
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 10.6 27.53 7.1 220 26.5
2 0 7.5 22.15 6.5 220 31.1
3 0 2.5 15.39 4.8 220 32.6
4 0 - 3.98 3.5 190 26.3
5 0 0.9 8.15 4.3 080 15.5
6 0 8.5 23.55 5.2 050 11.2
7 0 10.8 27.24 6.8 220 13.4
8 0 10.9 27.45 6.4 220 11.6
9 0 12.0 27.89 7.3 230 17.0
10 1 10.8 24.08 6.0 260 16.9
11 0 4.8 19.07 5.6 050 39.4
12 0 9.9 26.97 7.4 110 22.8
13 0 8.9 21.62 5.9 090 7.7
14 0 4.7 15.71 4.0 240 16.4
15 0 5.1 19.01 4.6 090 25.8
16 0 8.3 25.43 6.1 100 22.5
17 0 9.5 23.38 6.3 080 15.1
18 4 4.1 14.56 N.A. 280 28.0
19 0 0.6 8.20 3.4 210 44.5
20 0 5.7 18.85 4.0 110 24.0
21 0 10.1 24.86 5.5 110 12.0
22 0 6.5 16.29 4.5 140 11.9
23 0 6.6 19.91 4.9 200 15.6
24 0 3.7 17.01 5.3 210 25.0
25 0 6.3 18.63 4.2 220 23.9
26 0 5.1 17.01 5.1 200 18.0
27 0 1.6 10.46 2.8 160 20.0
28 0 4.0 12.85 3.7 190 20.8
29 0 5.0 19.65 4.4 130 20.0
30 0 5.2 18.54 4.6 100 25.0
31 0 7.2 22.88 4.8 100 25.5
Mean/Total 5 197.4 19.30 155.0& 100 21.5
Normal* 19.4§ 214.9 17.52 155.5 230 21.9
Station Hong   Kong
International   Airport
King's   Park Waglan   Island^

The minimum pressure recorded at the Hong Kong Observatory was 985.6 hectopascals at 0152 HKT on 19 July.

The maximum air temperature recorded at the Hong Kong Observatory was 34.3 degrees C at 1425 HKT on 18 July.

The minimum air temperature recorded at the Hong Kong Observatory was 23.9 degrees C at 0154 HKT on 6 July.

The maximum gust peak speed recorded at Waglan Island was 122 kilometres per hour from 250 degrees at 0150 HKT on 19 July.

The maximum instantaneous rate of rainfall recorded at the Hong Kong Observatory was 156 millimetres per hour at 1123 HKT on 5 July.

# 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

& Total for 30 days