Number of days available for climatic review
| Parameter | Jan | Feb | Mar | Apr | May | Jun |
| Tmax | 557 | 552 | 605 | 590 | 600 | 587 |
| Tmin | 559 | 551 | 602 | 588 | 606 | 594 |
| Duration of sunshine | 183 | 165 | 178 | 175 | 178 | 173 |
| Precipitation | 188 | 168 | 190 | 183 | 188 | 180 |
| Humidity/Visibility | 184 | 167 | 183 | 178 | 184 | 178 |
| Parameter | Jul | Aug | Sep | Oct | Nov | Dec |
| Tmax | 612 | 611 | 599 | 621 | 612 | 640 |
| Tmin | 609 | 615 | 599 | 637 | 616 | 640 |
| Duration of sunshine | 181 | 187 | 189 | 200 | 202 | 208 |
| Precipitation | 186 | 190 | 214 | 227 | 216 | 221 |
| Humidity/Visibility | 183 | 184 | 205 | 205 | 204 | 214 |
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. |
