Number of days available for climatic review
| Parameter | Jan | Feb | Mar | Apr | May | Jun |
| Tmax | 709 | 635 | 705 | 716 | 712 | 684 |
| Tmin | 712 | 637 | 711 | 719 | 718 | 685 |
| Duration of sunshine | 186 | 141 | 186 | 210 | 186 | 270 |
| Precipitation | 93 | 88 | 94 | 123 | 126 | 121 |
| Humidity/Visibility | 90 | 78 | 90 | 115 | 119 | 115 |
| Parameter | Jul | Aug | Sep | Oct | Nov | Dec |
| Tmax | 706 | 681 | 658 | 682 | 657 | 679 |
| Tmin | 711 | 682 | 658 | 681 | 659 | 680 |
| Duration of sunshine | 217 | 248 | 180 | 217 | 120 | 217 |
| Precipitation | 126 | 126 | 122 | 122 | 122 | 124 |
| Humidity/Visibility | 121 | 120 | 117 | 115 | 117 | 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. |
