Number of days available for climatic review
| Parameter | Jan | Feb | Mar | Apr | May | Jun |
| Tmax | 391 | 352 | 394 | 379 | 390 | 379 |
| Tmin | 395 | 355 | 394 | 378 | 393 | 379 |
| Duration of sunshine | 76 | 72 | 91 | 95 | 110 | 96 |
| Precipitation | 124 | 114 | 124 | 121 | 128 | 120 |
| Humidity/Visibility | 112 | 100 | 114 | 103 | 112 | 108 |
| Parameter | Jul | Aug | Sep | Oct | Nov | Dec |
| Tmax | 391 | 421 | 405 | 410 | 378 | 393 |
| Tmin | 396 | 420 | 408 | 401 | 384 | 393 |
| Duration of sunshine | 103 | 137 | 120 | 90 | 82 | 77 |
| Precipitation | 125 | 157 | 152 | 152 | 121 | 126 |
| Humidity/Visibility | 117 | 138 | 135 | 127 | 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. |
