Number of days available for climatic review
| Parameter | Jan | Feb | Mar | Apr | May | Jun |
| Tmax | 774 | 698 | 775 | 749 | 773 | 750 |
| Tmin | 774 | 701 | 774 | 749 | 774 | 748 |
| Duration of sunshine | 248 | 282 | 310 | 270 | 310 | 300 |
| Precipitation | 155 | 143 | 155 | 153 | 155 | 150 |
| Humidity/Visibility | 153 | 139 | 154 | 149 | 153 | 149 |
| Parameter | Jul | Aug | Sep | Oct | Nov | Dec |
| Tmax | 771 | 772 | 750 | 769 | 749 | 774 |
| Tmin | 769 | 775 | 748 | 767 | 747 | 774 |
| Duration of sunshine | 310 | 310 | 300 | 310 | 270 | 279 |
| Precipitation | 155 | 157 | 152 | 153 | 150 | 155 |
| Humidity/Visibility | 153 | 153 | 148 | 149 | 148 | 153 |
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. |
