Number of days available for climatic review
| Parameter | Jan | Feb | Mar | Apr | May | Jun |
| Tmax | 519 | 471 | 524 | 501 | 524 | 508 |
| Tmin | 524 | 470 | 523 | 500 | 523 | 505 |
| Duration of sunshine | 271 | 242 | 275 | 229 | 273 | 264 |
| Precipitation | 403 | 366 | 403 | 399 | 403 | 390 |
| Humidity/Visibility | 182 | 165 | 182 | 175 | 184 | 177 |
| Parameter | Jul | Aug | Sep | Oct | Nov | Dec |
| Tmax | 523 | 520 | 537 | 549 | 532 | 550 |
| Tmin | 524 | 522 | 531 | 550 | 533 | 553 |
| Duration of sunshine | 265 | 267 | 288 | 300 | 317 | 323 |
| Precipitation | 403 | 409 | 424 | 432 | 426 | 217 |
| Humidity/Visibility | 183 | 181 | 204 | 209 | 203 | 212 |
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. |
