Number of days available for climatic review
| Parameter | Jan | Feb | Mar | Apr | May | Jun |
| Tmax | 74 | 71 | 78 | 102 | 104 | 95 |
| Tmin | 86 | 80 | 87 | 111 | 119 | 109 |
| Duration of sunshine | 75 | 69 | 79 | 74 | 78 | 76 |
| Precipitation | 103 | 97 | 100 | 136 | 126 | 128 |
| Humidity/Visibility | 60 | 57 | 63 | 79 | 84 | 80 |
| Parameter | Jul | Aug | Sep | Oct | Nov | Dec |
| Tmax | 93 | 98 | 103 | 111 | 96 | 107 |
| Tmin | 103 | 111 | 116 | 118 | 105 | 118 |
| Duration of sunshine | 78 | 100 | 103 | 111 | 93 | 108 |
| Precipitation | 133 | 133 | 126 | 128 | 130 | 127 |
| Humidity/Visibility | 75 | 79 | 82 | 83 | 77 | 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. |
