Number of days available for climatic review
| Parameter | Jan | Feb | Mar | Apr | May | Jun |
| Tmax | 123 | 112 | 119 | 118 | 122 | 118 |
| Tmin | 121 | 113 | 115 | 117 | 123 | 118 |
| Duration of sunshine | 310 | 279 | 331 | 294 | 306 | 356 |
| Precipitation | 124 | 113 | 122 | 122 | 124 | 120 |
| Humidity/Visibility | 122 | 111 | 118 | 117 | 123 | 119 |
| Parameter | Jul | Aug | Sep | Oct | Nov | Dec |
| Tmax | 122 | 121 | 117 | 115 | 107 | 119 |
| Tmin | 118 | 123 | 115 | 112 | 108 | 119 |
| Duration of sunshine | 306 | 372 | 298 | 301 | 250 | 330 |
| Precipitation | 127 | 126 | 120 | 122 | 122 | 124 |
| Humidity/Visibility | 122 | 122 | 117 | 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. |
