Monthly Meteorological Normals for Hong Kong
- Monthly mean numbers of days with tropical cyclone warning signals and Strong Monsoon Signal in Hong Kong between 1981-2010
- Monthly mean of rainfall in Hong Kong between 1981-2010
- Monthly mean numbers of days with lightning, thunderstorm and fog reported at the Observatory between 1981-2010
- Monthly means of daily maximum, mean and minimum temperature recorded at the Observatory between 1981-2010
- Monthly means of relative humidity, dew point temperature, wet-bulb temperature and vapour pressure recorded at the Observatory between 1981-2010
- 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
- Monthly means of prevailing wind direction and mean wind speed recorded at the Observatory and Waglan Island between 1981-2010
- Monthly mean of atmospheric pressure recorded at the Observatory between 1981-2010
- 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
- Monthly mean of soil temperature recorded at the Observatory between 1981-2010
Month |
Number of Days with Tropical Cyclone Warning Signal |
Number of Days with Strong Monsoon Signal |
|||
---|---|---|---|---|---|
No. 1 and/or higher |
No. 3 and/or higher |
No. 8 and/or higher |
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. 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
Month |
Total (mm) |
Duration (hours) |
Number of Days with | ||
---|---|---|---|---|---|
0.1 mm or more |
25 mm or more |
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
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
Month |
Mean Daily Maximum (deg. C) |
Mean (deg. C) |
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
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 5.2. Monthly means of dew point temperature, web-bulb temperature and vapour pressure recorded at the Observatory between 1981-2010
Month |
Cloud Amount (%) |
Bright Sunshine | Daily Global Solar Radiation (MJ/m2) |
|
---|---|---|---|---|
Duration (hours) |
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 6.2. 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
Month |
Observatory | Waglan Island | ||
---|---|---|---|---|
Prevailing Wind Direction (deg.) |
Mean Wind Speed (km/h) |
Prevailing Wind Direction (deg.) |
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
Month |
Mean (hPa) |
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
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
Figure9.2. Monthly means of evaporation and potential evapotranspiration recorded at King's Park between 1981-2010
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 |
Figure10. Monthly mean of soil temperature recorded at the Observatory between 1981-2010