Number of days available for climatic review
| Parameter | Jan | Feb | Mar | Apr | May | Jun |
| Tmax | 744 | 668 | 744 | 719 | 741 | 718 |
| Tmin | 742 | 669 | 742 | 717 | 743 | 719 |
| Duration of sunshine | 103 | 99 | 127 | 123 | 148 | 129 |
| Precipitation | 715 | 644 | 713 | 691 | 713 | 690 |
| Humidity/Visibility | 153 | 138 | 153 | 147 | 153 | 147 |
| Parameter | Jul | Aug | Sep | Oct | Nov | Dec |
| Tmax | 741 | 741 | 718 | 738 | 718 | 743 |
| Tmin | 743 | 743 | 719 | 737 | 715 | 741 |
| Duration of sunshine | 139 | 149 | 132 | 108 | 86 | 82 |
| Precipitation | 715 | 715 | 692 | 711 | 690 | 713 |
| Humidity/Visibility | 153 | 152 | 148 | 149 | 147 | 153 |
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. |
