Number of days available for climatic review
| Parameter | Jan | Feb | Mar | Apr | May | Jun |
| Tmax | 702 | 633 | 709 | 683 | 708 | 686 |
| Tmin | 699 | 633 | 696 | 677 | 699 | 674 |
| Duration of sunshine | 142 | 137 | 139 | 138 | 126 | 128 |
| Precipitation | 155 | 141 | 157 | 151 | 155 | 150 |
| Humidity/Visibility | 134 | 124 | 132 | 131 | 136 | 130 |
| Parameter | Jul | Aug | Sep | Oct | Nov | Dec |
| Tmax | 697 | 695 | 673 | 703 | 687 | 683 |
| Tmin | 688 | 685 | 669 | 698 | 679 | 680 |
| Duration of sunshine | 171 | 176 | 160 | 130 | 111 | 142 |
| Precipitation | 153 | 143 | 140 | 152 | 152 | 128 |
| Humidity/Visibility | 131 | 127 | 125 | 126 | 127 | 118 |
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. |
