Number of days available for climatic review
| Parameter | Jan | Feb | Mar | Apr | May | Jun |
| Tmax | 108 | 90 | 109 | 116 | 121 | 118 |
| Tmin | 106 | 99 | 115 | 116 | 116 | 116 |
| Duration of sunshine | 55 | 45 | 51 | 55 | 58 | 56 |
| Precipitation | 123 | 111 | 124 | 121 | 124 | 121 |
| Humidity/Visibility | 103 | 99 | 116 | 115 | 120 | 117 |
| Parameter | Jul | Aug | Sep | Oct | Nov | Dec |
| Tmax | 121 | 129 | 117 | 117 | 117 | 106 |
| Tmin | 114 | 130 | 126 | 122 | 128 | 107 |
| Duration of sunshine | 45 | 48 | 52 | 44 | 55 | 72 |
| Precipitation | 132 | 153 | 141 | 139 | 146 | 128 |
| Humidity/Visibility | 120 | 127 | 125 | 122 | 118 | 107 |
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. |
