Number of days available for climatic review
| Parameter | Jan | Feb | Mar | Apr | May | Jun |
| Tmax | 280 | 252 | 285 | 270 | 287 | 273 |
| Tmin | 284 | 254 | 283 | 277 | 288 | 273 |
| Duration of sunshine | 119 | 110 | 85 | 126 | 104 | 109 |
| Precipitation | 66 | 56 | 65 | 76 | 93 | 90 |
| Humidity/Visibility | 59 | 54 | 59 | 73 | 85 | 87 |
| Parameter | Jul | Aug | Sep | Oct | Nov | Dec |
| Tmax | 281 | 281 | 273 | 283 | 270 | 281 |
| Tmin | 284 | 283 | 272 | 283 | 270 | 282 |
| Duration of sunshine | 115 | 147 | 144 | 141 | 150 | 156 |
| Precipitation | 99 | 93 | 94 | 99 | 99 | 124 |
| Humidity/Visibility | 90 | 91 | 85 | 89 | 95 | 99 |
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. |
