Number of days available for climatic review
| Parameter | Jan | Feb | Mar | Apr | May | Jun |
| Tmax | 833 | 749 | 830 | 802 | 832 | 804 |
| Tmin | 833 | 752 | 831 | 804 | 836 | 804 |
| Duration of sunshine | 298 | 239 | 268 | 256 | 261 | 255 |
| Precipitation | 186 | 172 | 186 | 187 | 186 | 183 |
| Humidity/Visibility | 182 | 163 | 180 | 175 | 182 | 175 |
| Parameter | Jul | Aug | Sep | Oct | Nov | Dec |
| Tmax | 829 | 829 | 829 | 855 | 827 | 859 |
| Tmin | 831 | 833 | 829 | 857 | 833 | 861 |
| Duration of sunshine | 257 | 290 | 270 | 314 | 306 | 355 |
| Precipitation | 192 | 194 | 216 | 219 | 216 | 223 |
| Humidity/Visibility | 180 | 179 | 201 | 206 | 200 | 209 |
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. |
