Number of days available for climatic review
| Parameter | Jan | Feb | Mar | Apr | May | Jun |
| Tmax | 590 | 553 | 614 | 589 | 606 | 593 |
| Tmin | 596 | 554 | 614 | 594 | 611 | 594 |
| Duration of sunshine | 186 | 254 | 279 | 270 | 310 | 270 |
| Precipitation | 188 | 169 | 189 | 184 | 186 | 184 |
| Humidity/Visibility | 176 | 163 | 179 | 174 | 179 | 176 |
| Parameter | Jul | Aug | Sep | Oct | Nov | Dec |
| Tmax | 603 | 602 | 607 | 627 | 615 | 608 |
| Tmin | 604 | 601 | 615 | 635 | 618 | 609 |
| Duration of sunshine | 248 | 279 | 240 | 310 | 270 | 248 |
| Precipitation | 186 | 192 | 216 | 216 | 210 | 197 |
| Humidity/Visibility | 174 | 169 | 195 | 201 | 197 | 182 |
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. |
