Number of days available for climatic review
| Parameter | Jan | Feb | Mar | Apr | May | Jun |
| Tmax | 555 | 501 | 554 | 549 | 576 | 565 |
| Tmin | 556 | 502 | 552 | 537 | 565 | 551 |
| Duration of sunshine | 0 | 28 | 31 | 30 | 62 | 30 |
| Precipitation | 98 | 89 | 97 | 117 | 134 | 129 |
| Humidity/Visibility | 90 | 83 | 89 | 98 | 112 | 111 |
| Parameter | Jul | Aug | Sep | Oct | Nov | Dec |
| Tmax | 579 | 572 | 564 | 579 | 568 | 585 |
| Tmin | 563 | 566 | 565 | 582 | 562 | 586 |
| Duration of sunshine | 31 | 62 | 60 | 62 | 60 | 31 |
| Precipitation | 136 | 133 | 123 | 124 | 125 | 128 |
| Humidity/Visibility | 112 | 107 | 113 | 115 | 115 | 121 |
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. |
