Number of days available for climatic review
| Parameter | Jan | Feb | Mar | Apr | May | Jun |
| Tmax | 817 | 752 | 830 | 800 | 827 | 797 |
| Tmin | 819 | 749 | 825 | 803 | 829 | 801 |
| Duration of sunshine | 173 | 153 | 171 | 169 | 166 | 160 |
| Precipitation | 193 | 173 | 192 | 185 | 196 | 187 |
| Humidity/Visibility | 179 | 164 | 182 | 174 | 179 | 174 |
| Parameter | Jul | Aug | Sep | Oct | Nov | Dec |
| Tmax | 827 | 824 | 820 | 847 | 833 | 853 |
| Tmin | 832 | 832 | 821 | 847 | 829 | 855 |
| Duration of sunshine | 173 | 176 | 182 | 192 | 193 | 195 |
| Precipitation | 198 | 198 | 217 | 220 | 218 | 229 |
| Humidity/Visibility | 179 | 177 | 199 | 201 | 201 | 208 |
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. |
