Number of days available for climatic review
| Parameter | Jan | Feb | Mar | Apr | May | Jun |
| Tmax | 106 | 88 | 105 | 121 | 132 | 126 |
| Tmin | 113 | 94 | 110 | 122 | 144 | 136 |
| Duration of sunshine | 89 | 77 | 92 | 83 | 90 | 83 |
| Precipitation | 132 | 119 | 129 | 157 | 157 | 151 |
| Humidity/Visibility | 90 | 79 | 88 | 98 | 112 | 107 |
| Parameter | Jul | Aug | Sep | Oct | Nov | Dec |
| Tmax | 125 | 122 | 125 | 127 | 108 | 118 |
| Tmin | 124 | 127 | 134 | 131 | 110 | 116 |
| Duration of sunshine | 51 | 61 | 81 | 83 | 107 | 106 |
| Precipitation | 155 | 156 | 148 | 149 | 134 | 139 |
| Humidity/Visibility | 103 | 95 | 110 | 104 | 88 | 94 |
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. |
