Number of days available for climatic review
| Parameter | Jan | Feb | Mar | Apr | May | Jun |
| Tmax | 87 | 83 | 101 | 89 | 87 | 78 |
| Tmin | 91 | 99 | 104 | 108 | 94 | 99 |
| Duration of sunshine | 89 | 97 | 98 | 102 | 92 | 96 |
| Precipitation | 128 | 116 | 131 | 127 | 135 | 132 |
| Humidity/Visibility | 84 | 84 | 94 | 91 | 85 | 88 |
| Parameter | Jul | Aug | Sep | Oct | Nov | Dec |
| Tmax | 97 | 90 | 79 | 80 | 101 | 87 |
| Tmin | 107 | 106 | 102 | 89 | 100 | 101 |
| Duration of sunshine | 103 | 105 | 100 | 87 | 99 | 96 |
| Precipitation | 138 | 131 | 126 | 121 | 136 | 137 |
| Humidity/Visibility | 94 | 92 | 85 | 75 | 89 | 87 |
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. |
