Number of days available for climatic review
| Parameter | Jan | Feb | Mar | Apr | May | Jun |
| Tmax | 823 | 742 | 831 | 803 | 830 | 792 |
| Tmin | 823 | 746 | 828 | 805 | 834 | 804 |
| Duration of sunshine | 134 | 124 | 137 | 128 | 136 | 136 |
| Precipitation | 155 | 141 | 155 | 151 | 155 | 150 |
| Humidity/Visibility | 145 | 133 | 147 | 138 | 145 | 145 |
| Parameter | Jul | Aug | Sep | Oct | Nov | Dec |
| Tmax | 828 | 849 | 826 | 850 | 828 | 825 |
| Tmin | 827 | 847 | 832 | 849 | 826 | 829 |
| Duration of sunshine | 141 | 157 | 167 | 146 | 111 | 139 |
| Precipitation | 160 | 184 | 180 | 184 | 179 | 159 |
| Humidity/Visibility | 148 | 160 | 167 | 163 | 148 | 146 |
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. |
