Number of days available for climatic review
| Parameter | Jan | Feb | Mar | Apr | May | Jun |
| Tmax | 556 | 510 | 579 | 561 | 575 | 529 |
| Tmin | 565 | 518 | 580 | 567 | 579 | 543 |
| Duration of sunshine | 131 | 119 | 130 | 123 | 137 | 131 |
| Precipitation | 160 | 142 | 168 | 170 | 162 | 154 |
| Humidity/Visibility | 145 | 134 | 145 | 131 | 130 | 125 |
| Parameter | Jul | Aug | Sep | Oct | Nov | Dec |
| Tmax | 568 | 596 | 576 | 599 | 575 | 564 |
| Tmin | 574 | 598 | 581 | 600 | 592 | 579 |
| Duration of sunshine | 134 | 154 | 152 | 140 | 96 | 120 |
| Precipitation | 160 | 187 | 188 | 190 | 199 | 182 |
| Humidity/Visibility | 128 | 138 | 145 | 165 | 157 | 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. |
