Number of days available for climatic review
| Parameter | Jan | Feb | Mar | Apr | May | Jun |
| Tmax | 1004 | 915 | 1012 | 981 | 1014 | 981 |
| Tmin | 975 | 885 | 987 | 953 | 985 | 952 |
| Duration of sunshine | 0 | 0 | 0 | 0 | 0 | 0 |
| Precipitation | 590 | 532 | 588 | 569 | 589 | 570 |
| Humidity/Visibility | 164 | 145 | 162 | 162 | 169 | 163 |
| Parameter | Jul | Aug | Sep | Oct | Nov | Dec |
| Tmax | 1010 | 1007 | 1006 | 1032 | 1010 | 1017 |
| Tmin | 989 | 985 | 979 | 1006 | 984 | 1013 |
| Duration of sunshine | 0 | 0 | 0 | 0 | 0 | 0 |
| Precipitation | 590 | 590 | 595 | 611 | 600 | 593 |
| Humidity/Visibility | 168 | 170 | 186 | 186 | 185 | 175 |
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. |
