Number of days available for climatic review
| Parameter | Jan | Feb | Mar | Apr | May | Jun |
| Tmax | 756 | 682 | 769 | 744 | 770 | 732 |
| Tmin | 763 | 690 | 764 | 744 | 773 | 743 |
| Duration of sunshine | 131 | 120 | 130 | 123 | 135 | 129 |
| Precipitation | 558 | 504 | 558 | 543 | 558 | 540 |
| Humidity/Visibility | 141 | 129 | 138 | 136 | 135 | 131 |
| Parameter | Jul | Aug | Sep | Oct | Nov | Dec |
| Tmax | 759 | 783 | 765 | 781 | 766 | 761 |
| Tmin | 761 | 782 | 763 | 786 | 764 | 761 |
| Duration of sunshine | 131 | 149 | 156 | 144 | 95 | 132 |
| Precipitation | 563 | 589 | 574 | 586 | 569 | 163 |
| Humidity/Visibility | 132 | 146 | 149 | 163 | 142 | 141 |
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. |