Number of days available for climatic review
| Parameter | Jan | Feb | Mar | Apr | May | Jun |
| Tmax | 555 | 502 | 549 | 540 | 555 | 537 |
| Tmin | 549 | 470 | 538 | 520 | 544 | 522 |
| Duration of sunshine | 176 | 134 | 169 | 157 | 171 | 162 |
| Precipitation | 510 | 513 | 528 | 519 | 524 | 506 |
| Humidity/Visibility | 182 | 157 | 179 | 171 | 180 | 173 |
| Parameter | Jul | Aug | Sep | Oct | Nov | Dec |
| Tmax | 553 | 555 | 568 | 583 | 569 | 590 |
| Tmin | 555 | 559 | 568 | 584 | 557 | 573 |
| Duration of sunshine | 182 | 185 | 203 | 209 | 200 | 198 |
| Precipitation | 498 | 498 | 514 | 527 | 526 | 563 |
| Humidity/Visibility | 183 | 182 | 204 | 209 | 202 | 206 |
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. |
