Number of days available for climatic review
| Parameter | Jan | Feb | Mar | Apr | May | Jun |
| Tmax | 630 | 568 | 619 | 580 | 618 | 603 |
| Tmin | 629 | 572 | 620 | 584 | 623 | 614 |
| Duration of sunshine | 101 | 91 | 84 | 72 | 96 | 97 |
| Precipitation | 133 | 124 | 135 | 131 | 139 | 133 |
| Humidity/Visibility | 104 | 93 | 93 | 75 | 90 | 96 |
| Parameter | Jul | Aug | Sep | Oct | Nov | Dec |
| Tmax | 633 | 619 | 593 | 617 | 599 | 627 |
| Tmin | 627 | 625 | 597 | 615 | 596 | 626 |
| Duration of sunshine | 99 | 93 | 81 | 91 | 84 | 91 |
| Precipitation | 140 | 137 | 133 | 136 | 140 | 163 |
| Humidity/Visibility | 98 | 91 | 76 | 83 | 87 | 99 |
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. |
