Number of days available for climatic review
| Parameter | Jan | Feb | Mar | Apr | May | Jun |
| Tmax | 554 | 503 | 551 | 559 | 584 | 561 |
| Tmin | 556 | 500 | 556 | 562 | 585 | 561 |
| Duration of sunshine | 87 | 80 | 90 | 111 | 111 | 113 |
| Precipitation | 93 | 85 | 94 | 116 | 121 | 117 |
| Humidity/Visibility | 89 | 83 | 90 | 110 | 118 | 114 |
| Parameter | Jul | Aug | Sep | Oct | Nov | Dec |
| Tmax | 584 | 583 | 568 | 579 | 564 | 586 |
| Tmin | 585 | 583 | 566 | 580 | 563 | 586 |
| Duration of sunshine | 119 | 118 | 116 | 112 | 109 | 119 |
| Precipitation | 125 | 125 | 117 | 122 | 120 | 124 |
| Humidity/Visibility | 121 | 119 | 117 | 114 | 112 | 120 |
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. |
