Number of days available for climatic review
| Parameter | Jan | Feb | Mar | Apr | May | Jun |
| Tmax | 274 | 250 | 302 | 294 | 300 | 293 |
| Tmin | 276 | 247 | 275 | 268 | 277 | 268 |
| Duration of sunshine | 76 | 58 | 73 | 73 | 72 | 66 |
| Precipitation | 150 | 139 | 178 | 178 | 185 | 175 |
| Humidity/Visibility | 67 | 63 | 85 | 93 | 97 | 93 |
| Parameter | Jul | Aug | Sep | Oct | Nov | Dec |
| Tmax | 295 | 297 | 292 | 298 | 281 | 277 |
| Tmin | 276 | 276 | 267 | 275 | 263 | 279 |
| Duration of sunshine | 77 | 76 | 78 | 76 | 79 | 77 |
| Precipitation | 187 | 189 | 202 | 185 | 206 | 184 |
| Humidity/Visibility | 92 | 95 | 100 | 85 | 90 | 83 |
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. |
