Number of days available for climatic review
| Parameter | Jan | Feb | Mar | Apr | May | Jun |
| Tmax | 519 | 482 | 537 | 543 | 560 | 542 |
| Tmin | 521 | 484 | 543 | 547 | 571 | 554 |
| Duration of sunshine | 86 | 72 | 82 | 83 | 82 | 81 |
| Precipitation | 139 | 131 | 129 | 148 | 161 | 159 |
| Humidity/Visibility | 92 | 79 | 88 | 105 | 119 | 112 |
| Parameter | Jul | Aug | Sep | Oct | Nov | Dec |
| Tmax | 562 | 560 | 547 | 552 | 498 | 529 |
| Tmin | 557 | 562 | 549 | 566 | 532 | 551 |
| Duration of sunshine | 81 | 82 | 82 | 83 | 108 | 112 |
| Precipitation | 154 | 158 | 151 | 153 | 129 | 139 |
| Humidity/Visibility | 112 | 106 | 116 | 114 | 78 | 85 |
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. |
