Number of days available for climatic review
| Parameter | Jan | Feb | Mar | Apr | May | Jun |
| Tmax | 743 | 669 | 743 | 718 | 742 | 719 |
| Tmin | 744 | 673 | 744 | 719 | 744 | 718 |
| Duration of sunshine | 81 | 101 | 126 | 128 | 143 | 130 |
| Precipitation | 157 | 141 | 155 | 151 | 159 | 150 |
| Humidity/Visibility | 153 | 139 | 153 | 148 | 153 | 148 |
| Parameter | Jul | Aug | Sep | Oct | Nov | Dec |
| Tmax | 740 | 739 | 720 | 738 | 719 | 743 |
| Tmin | 743 | 744 | 719 | 739 | 718 | 743 |
| Duration of sunshine | 141 | 151 | 132 | 108 | 86 | 80 |
| Precipitation | 155 | 157 | 152 | 153 | 150 | 155 |
| Humidity/Visibility | 153 | 152 | 147 | 148 | 148 | 152 |
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. |
