Number of days available for climatic review
| Parameter | Jan | Feb | Mar | Apr | May | Jun |
| Tmax | 740 | 668 | 742 | 730 | 769 | 747 |
| Tmin | 733 | 667 | 738 | 729 | 768 | 747 |
| Duration of sunshine | 294 | 284 | 279 | 313 | 337 | 321 |
| Precipitation | 95 | 86 | 94 | 106 | 124 | 120 |
| Humidity/Visibility | 92 | 84 | 92 | 104 | 123 | 119 |
| Parameter | Jul | Aug | Sep | Oct | Nov | Dec |
| Tmax | 772 | 773 | 746 | 765 | 741 | 767 |
| Tmin | 771 | 774 | 743 | 765 | 746 | 764 |
| Duration of sunshine | 362 | 352 | 307 | 356 | 278 | 303 |
| Precipitation | 127 | 126 | 120 | 121 | 120 | 123 |
| Humidity/Visibility | 123 | 122 | 118 | 118 | 119 | 123 |
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. |
