Bulletin issued at 00:15 HKT 24/May/2012

HKO Readings & Radiation level

Yesterday's Weather and Radiation Level:
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Hong Kong Observatory
Maximum Air Temperature                     28.5 C
Minimum Air Temperature                     24.5 C
Grass Minimum Temperature                   24.5 C
Relative Humidity                        67 - 83 Percent
Rainfall                                       0 mm 
Total rainfall since 1st January           621.5 mm
Against an average of                      547.1 mm

Other Stations                Min                  Max
King's Park                  23.8 C               27.6 C
Wong Chuk Hang               24.7 C               28.0 C
Ta Kwu Ling                  23.4 C               28.8 C
Lau Fau Shan                 24.0 C               30.5 C
Tai Po                       24.2 C               27.6 C
Sha Tin                      24.1 C               28.1 C
Tuen Mun                     24.4 C               30.4 C
Tseung Kwan O                24.0 C               27.3 C
Sai Kung                     24.6 C               27.1 C
Cheung Chau                  24.0 C               27.0 C
Chek Lap Kok                 25.3 C               30.3 C
Tsing Yi                     24.5 C               28.7 C
Shek Kong                    24.2 C               29.1 C
Tsuen Wan Ho Koon            22.8 C               29.0 C
Tsuen Wan Shing Mun Valley   24.0 C               28.4 C
Hong Kong Park               24.5 C               27.1 C
Shau Kei Wan                 23.9 C               25.9 C
Kowloon City                 24.4 C               29.0 C
Happy Valley                 24.7 C               28.5 C
Wong Tai Sin                 24.3 C               28.3 C
Stanley                      24.5 C               27.0 C
Kwun Tong                    23.8 C               26.8 C
Sham Shui Po                 24.4 C               28.7 C

Duration of sunshine (King's Park):              5.4 H
The mean UV index recorded at King's Park yesterday was 4,
the UV intensity was MODERATE.
The maximum UV index for yesterday was 9.
Sea Surface Temperature (Waglan Island):        // C
Yesterday's (23 May 2012) average ambient gamma radiation
dose rate taken outdoors in Hong Kong ranged from 0.08 to
0.15 microsievert per hour.  These are within the normal
range of fluctuation of the background radiation level in
Hong Kong (See Note). The average dose rates measured at the
radiation monitoring stations over various parts of the
territory were as follows :

Station                     Yesterday's average
                            (microsievert/hour)
Ping Chau                           0.09
Tap Mun                             0.08
Kat O                               0.10
Yuen Ng Fan                         0.11
Tai Mei Tuk                         0.11
Sha Tau Kok                         0.10
Kwun Tong                           0.12
Sai Wan Ho                          0.09
King's Park                         0.13
Tsim Bei Tsui                       0.13
Cape D'Aguilar                      0.13
Chek Lap Kok                        0.15   


Note
1.     From readings taken at various locations in Hong Kong during
       the period 1987-2011, the background ambient gamma radiation
       levels may vary between 0.06 and 0.30 microsievert per hour.

2.     The extent of health effects to a person as a result of
       exposure to radiation is expressed by a physical quantity
       called equivalent dose, in unit of sievert.  Protective
       action may be required if there is an increase in the
       ambient gamma dose rate above background such that the total
       additional dose is expected to exceed 5000 microsieverts in
       a relatively short period of time. For example, a dose of
       5000 microsieverts may be reached when the ambient gamma
       dose rate is 1000 microsieverts per hour (several thousand
       times above background) and lasts for 5 hours.

3.     The readings of ambient gamma radiation level from
       instrument are expressed in unit of gray, which is
       numerically equal to the gamma dose expressed in sievert.