Number of days available for climatic review
| Parameter | Jan | Feb | Mar | Apr | May | Jun |
| Tmax | 794 | 722 | 803 | 777 | 795 | 771 |
| Tmin | 790 | 723 | 801 | 773 | 795 | 772 |
| Duration of sunshine | 217 | 196 | 124 | 180 | 186 | 210 |
| Precipitation | 154 | 141 | 155 | 151 | 154 | 148 |
| Humidity/Visibility | 134 | 124 | 137 | 131 | 131 | 129 |
| Parameter | Jul | Aug | Sep | Oct | Nov | Dec |
| Tmax | 798 | 800 | 767 | 796 | 775 | 793 |
| Tmin | 797 | 788 | 768 | 795 | 771 | 793 |
| Duration of sunshine | 279 | 248 | 240 | 248 | 270 | 279 |
| Precipitation | 157 | 156 | 149 | 154 | 151 | 155 |
| Humidity/Visibility | 129 | 130 | 124 | 129 | 137 | 142 |
Climate data is usually derived from meteorological data of a certain number of years. The actual number of recorded years may vary from only a couple to 50 years or more. The quality of climate data depends on the number of available recorded years. Fewer years means less reliable data. The standart-period for reliable climate data is 30 years. For example, the mean monthly temperature for, let's say January, would ideally calculated from a total number of 930 recorded January-days. However, the usual number of recorded days is much smaller. The table above shows the actual number of recorded days for every parameter measured. |
Kingston