Number of days available for climatic review
| Parameter | Jan | Feb | Mar | Apr | May | Jun |
| Tmax | 77 | 71 | 75 | 80 | 84 | 99 |
| Tmin | 67 | 68 | 77 | 80 | 85 | 93 |
| Duration of sunshine | 31 | 56 | 62 | 30 | 62 | 30 |
| Precipitation | 104 | 93 | 106 | 97 | 96 | 106 |
| Humidity/Visibility | 85 | 79 | 85 | 85 | 89 | 98 |
| Parameter | Jul | Aug | Sep | Oct | Nov | Dec |
| Tmax | 115 | 114 | 116 | 111 | 100 | 92 |
| Tmin | 111 | 116 | 114 | 110 | 100 | 91 |
| Duration of sunshine | 0 | 31 | 30 | 62 | 30 | 62 |
| Precipitation | 134 | 127 | 127 | 123 | 128 | 139 |
| Humidity/Visibility | 117 | 117 | 114 | 113 | 109 | 116 |
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. |
