Number of days available for climatic review
| Parameter | Jan | Feb | Mar | Apr | May | Jun |
| Tmax | 737 | 658 | 739 | 715 | 732 | 713 |
| Tmin | 734 | 667 | 731 | 713 | 737 | 709 |
| Duration of sunshine | 281 | 374 | 343 | 333 | 349 | 302 |
| Precipitation | 188 | 169 | 187 | 181 | 186 | 180 |
| Humidity/Visibility | 175 | 161 | 178 | 174 | 174 | 172 |
| Parameter | Jul | Aug | Sep | Oct | Nov | Dec |
| Tmax | 736 | 736 | 735 | 761 | 736 | 758 |
| Tmin | 736 | 736 | 742 | 756 | 738 | 758 |
| Duration of sunshine | 377 | 471 | 485 | 435 | 358 | 362 |
| Precipitation | 186 | 190 | 210 | 215 | 210 | 217 |
| Humidity/Visibility | 175 | 178 | 198 | 199 | 191 | 199 |
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. |
