Number of days available for climatic review
| Parameter | Jan | Feb | Mar | Apr | May | Jun |
| Tmax | 92 | 82 | 93 | 105 | 122 | 118 |
| Tmin | 93 | 83 | 93 | 106 | 124 | 119 |
| Duration of sunshine | 0 | 0 | 0 | 0 | 0 | 0 |
| Precipitation | 93 | 85 | 94 | 109 | 124 | 120 |
| Humidity/Visibility | 92 | 84 | 92 | 104 | 123 | 118 |
| Parameter | Jul | Aug | Sep | Oct | Nov | Dec |
| Tmax | 120 | 122 | 120 | 116 | 118 | 119 |
| Tmin | 124 | 123 | 119 | 117 | 118 | 124 |
| Duration of sunshine | 0 | 0 | 0 | 0 | 0 | 0 |
| Precipitation | 126 | 129 | 120 | 122 | 120 | 124 |
| Humidity/Visibility | 123 | 122 | 118 | 117 | 118 | 124 |
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. |
