Number of days available for climatic review
| Parameter | Jan | Feb | Mar | Apr | May | Jun |
| Tmax | 102 | 97 | 109 | 108 | 104 | 98 |
| Tmin | 107 | 107 | 111 | 111 | 111 | 106 |
| Duration of sunshine | 102 | 159 | 109 | 104 | 198 | 136 |
| Precipitation | 127 | 118 | 124 | 122 | 131 | 123 |
| Humidity/Visibility | 102 | 97 | 108 | 108 | 103 | 103 |
| Parameter | Jul | Aug | Sep | Oct | Nov | Dec |
| Tmax | 111 | 110 | 98 | 100 | 107 | 105 |
| Tmin | 117 | 119 | 102 | 103 | 103 | 107 |
| Duration of sunshine | 143 | 174 | 130 | 93 | 130 | 169 |
| Precipitation | 129 | 129 | 121 | 115 | 124 | 130 |
| Humidity/Visibility | 110 | 111 | 101 | 95 | 106 | 105 |
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. |
