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Bulletin updated at 00:15 HKT
21/ Feb /2017

Yesterday's Weather and Radiation Level

Hong Kong Observatory:
Maximum Air Temperature: 25.5 C
Minimum Air Temperature: 18.3 C
Grass Minimum Temperature: 18.0 C
Relative Humidity: 69 - 91 percent
Rainfall: Trace

Total Rainfall since 1st January: 13.0 mm
Against an average of 64.3 mm

Other Stations
King's Park
17.8 C
26.0 C
Wong Chuk Hang
18.5 C
24.3 C
Ta Kwu Ling
17.1 C
27.3 C
Lau Fau Shan
16.7 C
24.6 C
Tai Po
17.1 C
23.2 C
Sha Tin
17.4 C
25.5 C
Tseung Kwan O
17.4 C
25.4 C
Sai Kung
17.5 C
22.5 C
Cheung Chau
17.5 C
23.3 C
Chek Lap Kok
18.5 C
25.7 C
Tsing Yi
18.1 C
25.8 C
Shek Kong
17.5 C
27.1 C
Tsuen Wan Ho Koon
17.0 C
24.6 C
Tsuen Wan Shing Mun Valley
17.7 C
26.7 C
Hong Kong Park
17.8 C
23.4 C
Shau Kei Wan
17.8 C
23.0 C
Kowloon City
17.6 C
26.5 C
Happy Valley
19.0 C
25.3 C
Wong Tai Sin
18.3 C
27.2 C
18.4 C
22.9 C
Kwun Tong
18.4 C
26.0 C
Sham Shui Po
18.1 C
26.0 C

Duration of Sunshine (King's Park): 5.5 H
The mean UV Index recorded at King's Park yesterday was 3,
the UV intensity was Moderate
The maximum UV Index for yesterday was 8.
Sea surface temperature (Waglan Island):18.2 C

Yesterday's (20 Feb) 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 :

Yesterday's average (microsievert/hour)
King's Park
Ping Chau
Tap Mun
Kat O
Yuen Ng Fan
Tai Mei Tuk
Sha Tau Kok
Kwun Tong
Sai Wan Ho
Tsim Bei Tsui

  1. From readings taken at various locations in Hong Kong during the period 1987-2016, 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.