| Date | Mean
  Pressure (hPa) | Air
  Temperature | Mean Relative Humidity (%) | Total Rainfall (mm) | ||
| Maximum (deg. C) | Mean (deg. C) | Minimum (deg. C) | ||||
| May 2018 | ||||||
| 01 | 1012.5 | 30.6 | 27.3 | 25.4 | 80 | Trace | 
| 02 | 1012.4 | 31.8 | 27.9 | 25.6 | 75 | 0 | 
| 03 | 1014.1 | 33.5 | 27.1 | 22.9 | 80 | 1.9 | 
| 04 | 1016.1 | 25.1 | 23.8 | 22.1 | 82 | 0.8 | 
| 05 | 1015.5 | 27.7 | 25.3 | 23.6 | 82 | Trace | 
| 06 | 1011.3 | 31 | 27.6 | 25.4 | 80 | 1 | 
| 07 | 1007.2 | 29.6 | 28 | 24.4 | 82 | 6.7 | 
| 08 | 1008.3 | 27.1 | 25.2 | 23.7 | 91 | 28.4 | 
| 09 | 1012.9 | 25.7 | 24.6 | 22.8 | 88 | 5.4 | 
| 10 | 1015 | 23.9 | 23 | 22.2 | 89 | 8 | 
| 11 | 1014.2 | 25.3 | 23.8 | 22.3 | 86 | 1 | 
| 12 | 1012.3 | 30.6 | 26.5 | 24.2 | 82 | 0 | 
| 13 | 1011 | 31.5 | 27.7 | 25.3 | 79 | 0 | 
| 14 | 1010 | 31.9 | 28.6 | 26.6 | 77 | 0 | 
| 15 | 1009.3 | 32.3 | 28.7 | 27.1 | 76 | 0 | 
| 16 | 1008.8 | 32.2 | 28.6 | 26.1 | 74 | 0 | 
| 17 | 1008.2 | 33.1 | 29.4 | 27.4 | 75 | 0 | 
| 18 | 1007.7 | 33.4 | 29.8 | 27.7 | 74 | 0 | 
| 19 | 1007.7 | 33.4 | 29.8 | 27.8 | 74 | 0 | 
| 20 | 1008.4 | 34.5 | 30.1 | 27.8 | 72 | 0 | 
| 21 | 1009.5 | 34.7 | 30.3 | 28.1 | 71 | 0 | 
| 22 | 1010.5 | 34.8 | 30.4 | 27.9 | 69 | 0 | 
| 23 | 1009.6 | 35.1 | 30.5 | 27.6 | 69 | 0 | 
| 24 | 1009.3 | 33.5 | 30 | 28.4 | 73 | 0 | 
| 25 | 1008.2 | 33.1 | 29.8 | 27.6 | 71 | Trace | 
| 26 | 1008.3 | 34.7 | 30.7 | 28.8 | 72 | 0.9 | 
| 27 | 1008.9 | 33.4 | 30 | 26.9 | 76 | 3.4 | 
| 28 | 1009 | 34.5 | 30.3 | 27.8 | 72 | 0 | 
| 29 | 1009.6 | 35.3 | 31.1 | 28.3 | 69 | 0 | 
| 30 | 1009.7 | 35.4 | 31.2 | 29 | 69 | 0 | 
| 31 | 1009.7 | 34.8 | 31.1 | 28.9 | 70 | 0 | 
Source: Hong Kong
Observatory – Hong Kong Observatory