Number of days available for climatic review
| Parameter | Jan | Feb | Mar | Apr | May | Jun |
| Tmax | 609 | 548 | 611 | 578 | 584 | 566 |
| Tmin | 610 | 553 | 612 | 576 | 586 | 569 |
| Duration of sunshine | 54 | 63 | 81 | 78 | 86 | 84 |
| Precipitation | 124 | 112 | 124 | 121 | 127 | 120 |
| Humidity/Visibility | 112 | 102 | 114 | 104 | 113 | 108 |
| Parameter | Jul | Aug | Sep | Oct | Nov | Dec |
| Tmax | 589 | 613 | 594 | 606 | 587 | 611 |
| Tmin | 591 | 615 | 592 | 604 | 595 | 609 |
| Duration of sunshine | 89 | 118 | 105 | 86 | 66 | 42 |
| Precipitation | 124 | 157 | 156 | 147 | 119 | 129 |
| Humidity/Visibility | 117 | 139 | 135 | 128 | 109 | 116 |
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. |
