Number of days available for climatic review
| Parameter | Jan | Feb | Mar | Apr | May | Jun |
| Tmax | 370 | 336 | 370 | 362 | 357 | 356 |
| Tmin | 372 | 336 | 370 | 373 | 398 | 384 |
| Duration of sunshine | 62 | 56 | 59 | 73 | 80 | 78 |
| Precipitation | 64 | 57 | 62 | 78 | 86 | 86 |
| Humidity/Visibility | 61 | 56 | 60 | 71 | 78 | 75 |
| Parameter | Jul | Aug | Sep | Oct | Nov | Dec |
| Tmax | 372 | 370 | 369 | 389 | 388 | 396 |
| Tmin | 380 | 391 | 387 | 396 | 389 | 397 |
| Duration of sunshine | 76 | 80 | 86 | 83 | 88 | 87 |
| Precipitation | 83 | 94 | 91 | 90 | 91 | 93 |
| Humidity/Visibility | 78 | 77 | 83 | 85 | 88 | 90 |
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. |
