Number of days available for climatic review
| Parameter | Jan | Feb | Mar | Apr | May | Jun |
| Tmax | 121 | 110 | 122 | 116 | 115 | 106 |
| Tmin | 123 | 113 | 121 | 119 | 119 | 117 |
| Duration of sunshine | 306 | 278 | 335 | 293 | 329 | 376 |
| Precipitation | 124 | 113 | 124 | 121 | 124 | 120 |
| Humidity/Visibility | 123 | 111 | 122 | 117 | 118 | 114 |
| Parameter | Jul | Aug | Sep | Oct | Nov | Dec |
| Tmax | 115 | 121 | 99 | 110 | 102 | 124 |
| Tmin | 118 | 121 | 114 | 113 | 109 | 123 |
| Duration of sunshine | 298 | 361 | 283 | 300 | 279 | 302 |
| Precipitation | 127 | 126 | 120 | 122 | 122 | 124 |
| Humidity/Visibility | 122 | 119 | 110 | 116 | 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. |
