Number of days available for climatic review
| Parameter | Jan | Feb | Mar | Apr | May | Jun |
| Tmax | 59 | 43 | 31 | 75 | 92 | 90 |
| Tmin | 60 | 56 | 61 | 74 | 92 | 89 |
| Duration of sunshine | 217 | 279 | 277 | 283 | 301 | 275 |
| Precipitation | 64 | 57 | 64 | 75 | 93 | 90 |
| Humidity/Visibility | 60 | 45 | 37 | 74 | 91 | 89 |
| Parameter | Jul | Aug | Sep | Oct | Nov | Dec |
| Tmax | 92 | 90 | 87 | 87 | 78 | 58 |
| Tmin | 86 | 91 | 86 | 88 | 79 | 59 |
| Duration of sunshine | 243 | 309 | 263 | 362 | 250 | 244 |
| Precipitation | 95 | 94 | 91 | 90 | 90 | 93 |
| Humidity/Visibility | 90 | 90 | 86 | 86 | 78 | 60 |
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. |
