Yesterday's Weather and Radiation Level

Bulletin issued at 00:15 HKT 01/May/2025

HKO Readings & Radiation level

Yesterday's Weather and Radiation Level:
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Hong Kong Observatory
Maximum Air Temperature                     29.2 C
Minimum Air Temperature                     23.1 C
Grass Minimum Temperature                   21.9 C
Relative Humidity                        63 - 86 Percent
Rainfall                                       0 mm 
Total rainfall since 1st January           125.5 mm
Against an average of                      300.4 mm

Other Stations                Min                  Max
King's Park                  22.2 C               28.4 C
Wong Chuk Hang               22.7 C               29.3 C
Ta Kwu Ling                  21.5 C               30.1 C
Lau Fau Shan                 21.0 C               29.8 C
Tai Po                       22.0 C               28.6 C
Sha Tin                      21.5 C               29.1 C
Tuen Mun                     22.5 C               29.2 C
Tseung Kwan O                20.9 C               28.5 C
Sai Kung                     21.6 C               27.7 C
Cheung Chau                  22.0 C               27.9 C
Chek Lap Kok                 23.3 C               29.5 C
Tsing Yi                     23.0 C               28.7 C
Shek Kong                    20.8 C               30.8 C
Tsuen Wan Ho Koon            20.2 C               28.5 C
Tsuen Wan Shing Mun Valley   21.3 C               29.9 C
Hong Kong Park               22.3 C               26.9 C
Shau Kei Wan                 21.9 C               26.1 C
Kowloon City                 21.8 C               28.9 C
Happy Valley                 22.5 C               29.6 C
Wong Tai Sin                 22.4 C               28.8 C
Stanley                      22.3 C               28.3 C
Kwun Tong                    21.7 C               28.5 C
Sham Shui Po                 22.3 C               29.6 C
Yuen Long Park               21.9 C               31.0 C
Tai Mei Tuk                  21.4 C               28.7 C

Duration of sunshine (King's Park):7.2 H    
The mean UV index recorded at King's Park yesterday was 4the UV intensity was MODERATE 
The maximum UV index for yesterday was 8.
Sea Surface Temperature (Waglan Island):        23.3 C
Yesterday's (30 Apr 2025) 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                           0.08
Tap Mun                             0.08
Kat O                               0.10
Yuen Ng Fan                         0.11
Tai Mei Tuk                         0.12
Sha Tau Kok                         0.10
Kwun Tong                           0.12
Sai Wan Ho                          0.08
King's Park                         0.14
Tsim Bei Tsui                       0.13
Cape D'Aguilar                      0.11
Chek Lap Kok                        0.15   


Note
1.     From readings taken at various locations in Hong Kong in the
       past, the hourly mean ambient gamma radiation dose rate may
       vary between 0.06 and 0.3 microsievert per hour. (1
       microsievert = 0.000001 sievert = 0.001 millisievert)

2.     Temporal variations are generally caused by changes in
       meteorological conditions such as rainfall, wind and
       barometric pressure.

3.     Spatial variations are generally caused by differences in
       the radioactive content of local rock and soil.

4.     The data displayed is provisional. Only limited data
       validation has been carried out.

5.     The range of relative humidity in the daily weather summary
       originates from the observer's reports of Hourly
       Readings of the day. This follows the long-term practice of
       collecting climatological data of the Hong Kong Observatory
       for over a century. It may differ from the relative humidity
       range derived from the 1-minute reports of the automatic
       weather station.