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Monthly Meteorological Normals for Hong Kong
Climatological Information Services > Meteorological Normals and Extremes > 1981-2010 Normals for Hong Kong (Grouped by element)

Monthly Meteorological Normals for Hong Kong

  1. Monthly mean numbers of days with tropical cyclone warning signals and Strong Monsoon Signal in Hong Kong between 1981-2010
  2. Monthly mean of rainfall in Hong Kong between 1981-2010
  3. Monthly mean numbers of days with lightning, thunderstorm and fog reported at the Observatory between 1981-2010
  4. Monthly means of daily maximum, mean and minimum temperature recorded at the Observatory between 1981-2010
  5. Monthly means of relative humidity, dew point temperature, wet-bulb temperature and vapour pressure recorded at the Observatory between 1981-2010
  6. Monthly means of cloud amount observed at the Observatory and sunshine duration and daily global solar radiation recorded at King's Park between 1981-2010
  7. Monthly means of prevailing wind direction and mean wind speed recorded at the Observatory and Waglan Island between 1981-2010
  8. Monthly mean of atmospheric pressure recorded at the Observatory between 1981-2010
  9. Monthly means of sea surface temperature recorded at North Point and Waglan Island, and evaporation and potential evapotranspiration recorded at King's Park between 1981-2010
  10. Monthly mean of soil temperature recorded at the Observatory between 1981-2010


 

Table 1.   Monthly mean numbers of days with tropical cyclone warning signals and Strong Monsoon Signal in Hong Kong between 1981-2010
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Month
 Number of Days with
Tropical Cyclone Warning Signal
Number of Days with
Strong Monsoon Signal
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No. 1 and/or
higher
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No. 3 and/or
higher
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No. 8 and/or
higher
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No. 9 and/or
No. 10
January - - - - 4.00
February - - - - 4.63
March - - - - 4.43
April 0.20 0.13 - - 2.90
May 0.40 0.23 0.07 - 1.53
June 1.80 0.93 0.20 0.03 1.27
July 3.33 1.73 0.57 0.03 0.70
August 3.83 1.50 0.57 0.10 0.27
September 3.83 1.87 0.53 0.10 1.97
October 2.00 1.03 0.07 - 4.13
November 0.40 0.07 - - 4.77
December - - - - 4.97
Year 15.80 7.50 2.00 0.27 35.57

Figure 1.1.   </B>Monthly mean number of days with tropical cyclone warning signals in Hong Kong between 1981-2010

Figure 1.1.   Monthly mean number of days with tropical cyclone warning signals in Hong Kong between 1981-2010


Figure 1.2. Monthly mean number of days with Strong Monsoon Signal in Hong Kong between 1981-2010

Figure 1.2.   Monthly mean number of days with Strong Monsoon Signal in Hong Kong between 1981-2010

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Table 2.   Monthly mean of rainfall in Hong Kong between 1981-2010
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Month
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Total
(mm)
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Duration
(hours)
Number of Days with
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0.1 mm
or more
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25 mm
or more
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50 mm
or more
January 24.7 46 5.37 0.23 0.00
February 54.4 89 9.07 0.53 0.10
March 82.2 101 10.90 0.87 0.37
April 174.7 99 12.00 2.23 1.10
May 304.7 106 14.67 3.97 1.73
June 456.1 111 19.07 5.27 2.60
July 376.5 85 17.60 4.60 2.27
August 432.2 97 16.93 5.37 2.47
September 327.6 78 14.67 3.80 2.00
October 100.9 46 7.43 1.20 0.70
November 37.6 38 5.47 0.43 0.13
December 26.8 40 4.47 0.20 0.07
Year 2398.5 935 137.63 28.70 13.53

Figure 2. Monthly mean of rainfall in Hong Kong between 1981-2010

Figure 2.   Monthly mean of rainfall in Hong Kong between 1981-2010

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Table 3.   Monthly mean numbers of days with lightning,thunderstorm and fog reported at the Observatory between 1981-2010
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Month
Number of Days with
Lightning
Number of Days with
Thunderstorm
Number of Days with Fog
(Visibility < 1000 m)
January 0.13 0.13 0.30
February 0.90 0.87 1.20
March 1.90 1.77 2.00
April 4.13 3.50 1.03
May 6.77 5.20 0.07
June 9.07 7.03 -
July 9.77 6.60 -
August 11.23 8.33 -
September 7.13 4.40 -
October 0.97 0.53 -
November 0.27 0.23 -
December 0.03 - 0.03
Year 52.30 38.60 4.63

Figure 3. Monthly mean numbers of days with lightning, thunderstorm and fog reported at the Observatory between 1981-2010

Figure 3.    Monthly mean numbers of days with lightning, thunderstorm and fog reported at the Observatory between 1981-2010

 

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Table 4.   Monthly means of daily maximum, mean and minimum temperature recorded at the Observatory between 1981-2010
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Month
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Mean Daily
Maximum
(deg. C)
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Mean
(deg. C)
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Mean Daily
Minimum
(deg. C)
January 18.6 16.3 14.5
February 18.9 16.8 15.0
March 21.4 19.1 17.2
April 25.0 22.6 20.8
May 28.4 25.9 24.1
June 30.2 27.9 26.2
July 31.4 28.8 26.8
August 31.1 28.6 26.6
September 30.1 27.7 25.8
October 27.8 25.5 23.7
November 24.1 21.8 19.8
December 20.2 17.9 15.9
Year 25.6 23.3 21.4

Figure 4. Monthly means of daily maximum, mean and minimum temperature recorded at the Observatory between 1981-2010

Figure 4.   Monthly means of daily maximum, mean and minimum temperature recorded at the Observatory between 1981-2010

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Table 5.   Monthly means of relative humidity, dew point temperature, wet-bulb temperature and vapour pressure recorded at the Observatory  between 1981-2010
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Month
Relative Humidity (%)  Dew Point 
Temperature
(deg. C)
Wet-bulb
Temperature
(deg. C)
Vapour
 Pressure 
(hPa)
    Mean     Mean at
0200 hours
Mean at
1400 hours
January 74 78 66 11.4 13.8 14.0
February 80 83 73 13.0 14.7 15.5
March 82 85 75 15.7 17.2 18.4
April 83 87 77 19.4 20.6 23.0
May 83 87 76 22.6 23.7 27.7
June 82 86 77 24.6 25.6 31.0
July 81 85 74 25.1 26.1 31.8
August 81 85 74 25.0 26.0 31.7
September 78 83 72 23.4 24.8 29.0
October 73 78 66 20.2 22.1 24.1
November 71 76 63 16.0 18.4 18.8
December 69 74 61 11.9 14.8 14.6
Year 78 82 71 19.0 20.6 23.3

Figure 5.1. Monthly mean of relative humidity recorded at the Observatory between 1981-2010

Figure 5.1.    Monthly mean of relative humidity recorded at the Observatory between 1981-2010


Figure 5.2. Monthly means of dew point temperature, web-bulb temperature and vapour pressure recorded at the Observatory between 1981-2010

Figure 5.2.    Monthly means of dew point temperature, web-bulb temperature and vapour pressure recorded at the Observatory between 1981-2010

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Table 6.   Monthly means of cloud amount observed at the Observatory and sunshine duration and daily global solar radiation recorded at King's Park between 1981-2010
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Month
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Cloud Amount
(%)
Bright Sunshine blank space
Daily Global
Solar Radiation
(MJ/m2)
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Duration
(hours)
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Percentage
of Possible
January 61 143.0 42 10.17
February 74 94.2 29 9.39
March 79 90.8 24 9.96
April 81 101.7 27 11.60
May 76 140.4 34 14.19
June 77 146.1 36 14.19
July 69 212.0 51 17.17
August 69 188.9 47 15.63
September 66 172.3 47 14.61
October 58 193.9 54 14.05
November 54 180.1 54 12.28
December 52 172.2 51 10.89
Year 68 1835.6 42 12.85

Figure 6.1.    Monthly mean of cloud amount recorded at the Observatory between 1981-2010   

Figure 6.1.    Monthly mean of cloud amount recorded at the Observatory between 1981-2010


Figure 6.2.    Monthly mean of sunshine duration recorded at King's Park between 1981-2010

Figure 6.2.    Monthly mean of sunshine duration recorded at King's Park between 1981-2010


Figure 6.3.    Monthly mean of daily global solar radiation recorded at King's Park between 1981-2010

Figure 6.3.    Monthly mean of daily global solar radiation recorded at King's Park between 1981-2010

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Table 7.      Monthly means of prevailing wind direction and mean wind speed recorded at the Observatory and Waglan Island between
1981-2010
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Month
Observatory Waglan Island
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Prevailing Wind
Direction
(deg.)
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Mean Wind
Speed (km/h)
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Prevailing Wind
Direction
(deg.)
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Mean Wind
Speed (km/h)
January 090 10.6 060 25.3
February 090 11.7 070 24.5
March 090 12.0 060 23.0
April 090 11.5 070 20.9
May 090 10.7 080 19.7
June 090 10.6 220 22.9
July 260 10.7 230 21.3
August 090 10.2 230 19.4
September 090 11.4 090 22.6
October 090 12.1 080 27.4
November 090 11.0 080 27.0
December 090 10.0 070 26.0
Year 090 11.0 080 23.3

Figure 7. Monthly means of prevailing wind direction and mean wind speed recorded at the Observatory and Waglan Island between 1981-2010

Figure 7.   Monthly means of prevailing wind direction and mean wind speed recorded at the Observatory and Waglan Island between 1981-2010

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Table 8.   Monthly mean of atmospheric pressure recorded at the Observatory between 1981-2010
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Month
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Mean (hPa)
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Mean Diurnal
Range (hPa)
January 1020.3 4.1
February 1018.5 4.2
March 1016.0 4.3
April 1012.9 3.9
May 1009.3 3.5
June 1006.1 3.2
July 1005.7 3.4
August 1005.2 3.5
September 1008.9 3.6
October 1014.1 3.6
November 1017.7 3.9
December 1020.5 4.1
Year 1012.9 3.8

Figure8. Monthly mean of atmospheric pressure recorded at the Observatory between 1981-2010

Figure8.   Monthly mean of atmospheric pressure recorded at the Observatory between 1981-2010

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Table 9.   Monthly means of sea surface temperature recorded at North Point and Waglan Island, and evaporation and potential evapotranspiration recorded at King's Park between 1981-2010
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Month
Sea Surface Temperature (deg. C)  Evaporation
(mm)
Potential
Evapotranspiration
(mm)
North Point Waglan Island
 0700 hours   1400 hours  0700 or
 1100 hours 
1400 or
 1700 hours 
January 17.4 17.7 17.6 17.7 71.3 61.2
February 16.8 17.1 16.8 16.9 59.9 58.7
March 18.0 18.3 18.0 18.2 70.5 65.3
April 21.0 21.4 20.9 21.1 83.8 81.6
May 24.5 25.0 24.6 24.8 110.7 101.8
June 26.5 26.9 26.5 26.7 117.1 108.0
July 26.6 27.1 26.9 27.2 146.2 125.9
August 26.6 27.1 27.1 27.3 134.9 120.6
September 27.1 27.5 27.4 27.7 125.9 100.3
October 26.3 26.6 26.4 26.6 123.9 96.0
November 23.4 23.7 23.3 23.5 99.5 78.8
December 19.8 20.1 19.8 20.0 83.7 64.1
Year 22.8 23.2 22.9 23.2 1227.3 1062.4

Figure9.1. Monthly means of sea surface temperature recorded at North Point and Waglan Island between 1981-2010   

Figure9.1.   Monthly means of sea surface temperature recorded at North Point and Waglan Island between 1981-2010



Figure9.2. Monthly means of evaporation and potential evapotranspiration recorded at King's Park between 1981-2010   

Figure9.2.   Monthly means of evaporation and potential evapotranspiration recorded at King's Park between 1981-2010

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Table 10.   Monthly mean of soil temperature recorded at the Observatory between 1981-2010
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Month
0.5 m 1.0 m 1.5 m
 0700 hours 
(deg. C)
 1900 hours 
(deg. C)
 0700 hours 
(deg. C)
 1900 hours 
(deg. C)
 0700 hours 
(deg. C)
 1900 hours 
(deg. C)
January 18.8 18.7 20.3 20.3 21.5 21.5
February 19.0 18.9 19.9 19.9 20.7 20.7
March 20.9 20.9 21.0 21.0 21.3 21.3
April 23.5 23.5 22.9 23.0 22.6 22.7
May 26.6 26.6 25.6 25.7 24.8 24.9
June 28.5 28.5 27.6 27.7 26.9 26.9
July 29.8 29.8 29.0 29.0 28.2 28.3
August 30.0 29.9 29.4 29.4 28.9 28.9
September 29.6 29.5 29.3 29.3 29.1 29.0
October 27.8 27.7 28.1 28.1 28.2 28.2
November 24.5 24.4 25.7 25.6 26.4 26.4
December 21.0 21.0 22.8 22.8 24.1 24.1
Year 25.0 25.0 25.1 25.2 25.2 25.2

Monthly mean of soil temperature recorded at the Observatory between 1981-2010

Figure10.   Monthly mean of soil temperature recorded at the Observatory between 1981-2010

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Last revision date: <21 Dec 2012>