Number of days available for climatic review
| Parameter | Jan | Feb | Mar | Apr | May | Jun |
| Tmax | 527 | 483 | 534 | 519 | 526 | 513 |
| Tmin | 542 | 499 | 543 | 533 | 545 | 522 |
| Duration of sunshine | 98 | 100 | 103 | 108 | 106 | 103 |
| Precipitation | 130 | 121 | 125 | 123 | 129 | 127 |
| Humidity/Visibility | 86 | 86 | 92 | 91 | 86 | 84 |
| Parameter | Jul | Aug | Sep | Oct | Nov | Dec |
| Tmax | 540 | 535 | 514 | 532 | 516 | 535 |
| Tmin | 542 | 547 | 519 | 536 | 508 | 548 |
| Duration of sunshine | 103 | 114 | 99 | 96 | 90 | 111 |
| Precipitation | 134 | 129 | 128 | 129 | 131 | 131 |
| Humidity/Visibility | 89 | 92 | 85 | 83 | 81 | 97 |
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. |
