Number of days available for climatic review
| Parameter | Jan | Feb | Mar | Apr | May | Jun |
| Tmax | 629 | 566 | 637 | 621 | 635 | 623 |
| Tmin | 611 | 558 | 635 | 597 | 601 | 593 |
| Duration of sunshine | 124 | 56 | 124 | 30 | 93 | 90 |
| Precipitation | 608 | 554 | 617 | 597 | 618 | 598 |
| Humidity/Visibility | 112 | 99 | 127 | 114 | 114 | 120 |
| Parameter | Jul | Aug | Sep | Oct | Nov | Dec |
| Tmax | 622 | 633 | 632 | 669 | 635 | 637 |
| Tmin | 590 | 634 | 625 | 644 | 626 | 625 |
| Duration of sunshine | 155 | 62 | 60 | 155 | 90 | 93 |
| Precipitation | 621 | 622 | 625 | 643 | 619 | 198 |
| Humidity/Visibility | 116 | 118 | 140 | 151 | 144 | 138 |
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. |
