Monthly Meteorological Normals for Hong Kong (1991-2020)
- Monthly mean numbers of days with tropical cyclone warning signals and Strong Monsoon Signal in Hong Kong between 1991-2020
- Monthly mean of rainfall in Hong Kong between 1991-2020
- Monthly mean numbers of days with lightning, thunderstorm and fog reported at the Observatory between 1991-2020
- Monthly means of daily maximum, mean and minimum temperature recorded at the Observatory between 1991-2020
- Monthly means of relative humidity, dew point temperature, wet-bulb temperature and vapour pressure recorded at the Observatory between 1991-2020
- Monthly means of cloud amount observed at the Observatory and sunshine duration and daily global solar radiation recorded at King's Park between 1991-2020
- Monthly means of prevailing wind direction and mean wind speed recorded at the Observatory and Waglan Island between 1991-2020
- Monthly mean of atmospheric pressure recorded at the Observatory between 1991-2020
- Monthly means of sea surface temperature recorded at North Point and Waglan Island, and evaporation and potential evapotranspiration recorded at King's Park between 1991-2020
- Monthly mean of soil temperature recorded at the Observatory between 1991-2020
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 | - | - | - | - | 3.63 |
February | - | - | - | - | 3.90 |
March | - | - | - | - | 4.93 |
April | 0.20 | 0.13 | - | - | 2.37 |
May | 0.27 | 0.13 | 0.03 | - | 1.50 |
June | 2.00 | 1.00 | 0.27 | 0.03 | 0.90 |
July | 3.13 | 1.53 | 0.53 | 0.10 | 0.90 |
August | 4.17 | 1.90 | 0.80 | 0.17 | 0.37 |
September | 3.83 | 1.87 | 0.67 | 0.10 | 2.03 |
October | 1.70 | 0.73 | 0.13 | - | 4.10 |
November | 0.57 | 0.13 | - | - | 4.30 |
December | - | - | - | - | 5.13 |
Year | 15.87 | 7.43 | 2.43 | 0.40 | 34.07 |
Figure 1.1. Monthly mean number of days with tropical cyclone warning signals in Hong Kong between 1991-2020
Figure 1.2. Monthly mean number of days with Strong Monsoon Signal in Hong Kong between 1991-2020
Month |
Total (mm) |
Duration (hours) |
Number of Days with | ||
---|---|---|---|---|---|
0.1 mm or more |
25 mm or more |
50 mm or more |
|||
January | 33.2 | 55 | 5.70 | 0.43 | 0.00 |
February | 38.9 | 87 | 7.97 | 0.33 | 0.07 |
March | 75.3 | 108 | 10.50 | 0.77 | 0.30 |
April | 153.0 | 98 | 11.37 | 1.87 | 0.87 |
May | 290.6 | 112 | 15.37 | 3.93 | 1.63 |
June | 491.5 | 118 | 19.33 | 6.03 | 2.90 |
July | 385.8 | 93 | 18.43 | 4.83 | 2.10 |
August | 453.2 | 103 | 17.50 | 5.83 | 2.63 |
September | 321.4 | 77 | 14.90 | 3.77 | 1.97 |
October | 120.3 | 50 | 7.83 | 1.33 | 0.77 |
November | 39.3 | 45 | 5.70 | 0.40 | 0.13 |
December | 28.8 | 48 | 5.30 | 0.17 | 0.03 |
Year | 2431.2 | 993 | 139.90 | 29.70 | 13.40 |
Figure 2. Monthly mean of rainfall in Hong Kong between 1991-2020
Month |
Number of Days with Lightning |
Number of Days with Thunderstorm |
Number of Days with Fog (Visibility < 1000 m) |
---|---|---|---|
January | 0.23 | 0.23 | 0.20 |
February | 0.60 | 0.60 | 1.10 |
March | 1.53 | 1.37 | 1.47 |
April | 3.77 | 3.13 | 0.83 |
May | 7.70 | 5.87 | 0.07 |
June | 10.70 | 8.13 | - |
July | 10.80 | 7.97 | - |
August | 11.53 | 8.90 | - |
September | 7.07 | 5.07 | - |
October | 1.17 | 0.83 | - |
November | 0.23 | 0.17 | - |
December | 0.03 | - | 0.03 |
Year | 55.37 | 42.27 | 3.70 |
Figure 3. Monthly mean numbers of days with lightning, thunderstorm and fog reported at the Observatory between 1991-2020
Month |
Mean Daily Maximum (deg. C) |
Mean (deg. C) |
Mean Daily Minimum (deg. C) |
---|---|---|---|
January | 18.7 | 16.5 | 14.6 |
February | 19.4 | 17.1 | 15.3 |
March | 21.9 | 19.5 | 17.6 |
April | 25.6 | 23.0 | 21.1 |
May | 28.8 | 26.3 | 24.5 |
June | 30.7 | 28.3 | 26.5 |
July | 31.6 | 28.9 | 26.9 |
August | 31.3 | 28.7 | 26.7 |
September | 30.5 | 27.9 | 26.1 |
October | 28.1 | 25.7 | 23.9 |
November | 24.5 | 22.2 | 20.3 |
December | 20.4 | 18.2 | 16.2 |
Year | 26.0 | 23.5 | 21.6 |
Figure 4. Monthly means of daily maximum, mean and minimum temperature recorded at the Observatory between 1991-2020
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 | 67 | 11.7 | 14.0 | 14.2 |
February | 79 | 83 | 72 | 13.2 | 15.0 | 15.7 |
March | 82 | 86 | 75 | 16.1 | 17.5 | 18.7 |
April | 83 | 87 | 75 | 19.7 | 20.9 | 23.4 |
May | 83 | 87 | 76 | 23.0 | 24.0 | 28.2 |
June | 82 | 86 | 76 | 24.9 | 25.9 | 31.6 |
July | 81 | 85 | 74 | 25.2 | 26.3 | 32.1 |
August | 81 | 86 | 74 | 25.1 | 26.1 | 31.8 |
September | 78 | 82 | 71 | 23.6 | 25.0 | 29.4 |
October | 73 | 77 | 65 | 20.2 | 22.2 | 24.1 |
November | 72 | 77 | 65 | 16.7 | 19.0 | 19.6 |
December | 70 | 75 | 63 | 12.4 | 15.1 | 15.0 |
Year | 78 | 82 | 71 | 19.3 | 20.9 | 23.7 |
Figure 5.1. Monthly mean of relative humidity recorded at the Observatory between 1991-2020
Figure 5.2. Monthly means of dew point temperature, web-bulb temperature and vapour pressure recorded at the Observatory between 1991-2020
Month |
Cloud Amount (%) |
Bright Sunshine | Daily Global Solar Radiation (MJ/m2) |
|
---|---|---|---|---|
Duration (hours) |
Percentage of Possible |
|||
January | 62 | 145.8 | 43 | 10.55 |
February | 72 | 101.7 | 32 | 10.24 |
March | 77 | 100.0 | 27 | 10.71 |
April | 77 | 113.2 | 30 | 12.52 |
May | 76 | 138.8 | 34 | 14.46 |
June | 77 | 144.3 | 36 | 14.61 |
July | 72 | 197.3 | 48 | 17.22 |
August | 70 | 182.1 | 46 | 15.73 |
September | 66 | 174.4 | 47 | 14.99 |
October | 58 | 197.8 | 55 | 14.52 |
November | 58 | 172.3 | 52 | 12.26 |
December | 57 | 161.6 | 48 | 10.91 |
Year | 68 | 1829.3 | 41 | 13.23 |
Figure 6.1. Monthly mean of cloud amount recorded at the Observatory between 1991-2020
Figure 6.2. Monthly mean of sunshine duration recorded at King's Park between 1991-2020
Figure 6.3. Monthly mean of daily global solar radiation recorded at King's Park between 1991-2020
Month |
Observatory | Waglan Island | ||
---|---|---|---|---|
Prevailing Wind Direction (deg.) |
Mean Wind Speed (km/h) |
Prevailing Wind Direction (deg.) |
Mean Wind Speed (km/h) |
|
January | 090 | 9.4 | 60 | 25.1 |
February | 090 | 10.7 | 60 | 24.2 |
March | 090 | 11.1 | 60 | 23.0 |
April | 090 | 9.7 | 70 | 20.5 |
May | 090 | 9.3 | 80 | 19.8 |
June | 260 | 9.2 | 220 | 21.6 |
July | 260 | 9.9 | 230 | 21.3 |
August | 260 | 9.1 | 230 | 18.8 |
September | 090 | 10.1 | 80 | 21.4 |
October | 090 | 10.6 | 80 | 26.3 |
November | 090 | 9.9 | 70 | 26.6 |
December | 090 | 9.2 | 10 | 26.4 |
Year | 090 | 9.9 | 70 | 22.9 |
Figure 7. Monthly means of prevailing wind direction and mean wind speed recorded at the Observatory and Waglan Island between 1991-2020
Month |
Mean (hPa) |
Mean Diurnal Range (hPa) |
---|---|---|
January | 1020.1 | 4.5 |
February | 1018.7 | 4.5 |
March | 1016.1 | 4.7 |
April | 1013.0 | 4.3 |
May | 1009.3 | 3.8 |
June | 1006.1 | 3.5 |
July | 1005.6 | 3.7 |
August | 1005.2 | 4.0 |
September | 1008.8 | 3.9 |
October | 1014.0 | 3.9 |
November | 1017.3 | 4.2 |
December | 1020.1 | 4.4 |
Year | 1012.9 | 4.1 |
Figure8. Monthly mean of atmospheric pressure recorded at the Observatory between 1991-2020
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 | 17.6 | 17.9 | 17.7 | 17.9 | 69.1 | 59.2 |
February | 17.0 | 17.3 | 17.0 | 17.2 | 60.4 | 54.7 |
March | 18.3 | 18.7 | 18.4 | 18.6 | 73.2 | 66.3 |
April | 21.4 | 21.8 | 21.3 | 21.7 | 87.2 | 80.3 |
May | 24.7 | 25.2 | 24.7 | 25.2 | 109.8 | 95.4 |
June | 26.6 | 27.0 | 26.6 | 27.0 | 113.8 | 96.5 |
July | 26.5 | 27.0 | 26.5 | 27.0 | 142.0 | 113.8 |
August | 26.6 | 27.0 | 26.8 | 27.2 | 129.7 | 108.6 |
September | 27.0 | 27.4 | 27.3 | 27.6 | 122.8 | 94.8 |
October | 26.5 | 26.7 | 26.6 | 26.9 | 122.6 | 93.0 |
November | 23.7 | 24.0 | 23.6 | 23.9 | 95.1 | 78.5 |
December | 20.0 | 20.3 | 20.1 | 20.3 | 80.9 | 63.4 |
Year | 23.0 | 23.3 | 23.1 | 23.4 | 1204.1 | 1010.8 |
Figure9.1. Monthly means of sea surface temperature recorded at North Point and Waglan Island between 1991-2020
Figure9.2. Monthly means of evaporation and potential evapotranspiration recorded at King's Park between 1991-2020
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 | 19.1 | 19.0 | 20.7 | 20.7 | 22.0 | 22.0 |
February | 19.2 | 19.2 | 20.2 | 20.2 | 21.1 | 21.1 |
March | 21.3 | 21.3 | 21.5 | 21.5 | 21.7 | 21.7 |
April | 23.9 | 23.9 | 23.4 | 23.4 | 23.0 | 23.0 |
May | 26.8 | 26.8 | 25.9 | 25.9 | 25.0 | 25.1 |
June | 28.7 | 28.7 | 27.9 | 28.0 | 27.1 | 27.1 |
July | 29.8 | 29.7 | 29.1 | 29.1 | 28.3 | 28.3 |
August | 29.8 | 29.8 | 29.4 | 29.4 | 28.9 | 28.9 |
September | 29.5 | 29.4 | 29.4 | 29.3 | 29.0 | 29.0 |
October | 27.7 | 27.6 | 28.2 | 28.2 | 28.2 | 28.2 |
November | 24.8 | 24.7 | 26.0 | 25.9 | 26.6 | 26.6 |
December | 21.6 | 21.6 | 23.5 | 23.4 | 24.6 | 24.6 |
Year | 25.2 | 25.1 | 25.4 | 25.4 | 25.5 | 25.5 |
Figure10. Monthly mean of soil temperature recorded at the Observatory between 1991-2020