Number of days available for climatic review
| Parameter | Jan | Feb | Mar | Apr | May | Jun |
| Tmax | 155 | 139 | 154 | 149 | 153 | 150 |
| Tmin | 153 | 140 | 154 | 149 | 153 | 147 |
| Duration of sunshine | 153 | 139 | 151 | 146 | 152 | 145 |
| Precipitation | 155 | 140 | 155 | 151 | 155 | 150 |
| Humidity/Visibility | 152 | 139 | 154 | 147 | 153 | 148 |
| Parameter | Jul | Aug | Sep | Oct | Nov | Dec |
| Tmax | 148 | 152 | 148 | 149 | 148 | 154 |
| Tmin | 146 | 154 | 147 | 150 | 147 | 152 |
| Duration of sunshine | 146 | 152 | 144 | 144 | 148 | 151 |
| Precipitation | 150 | 160 | 150 | 153 | 150 | 155 |
| Humidity/Visibility | 150 | 150 | 147 | 149 | 147 | 153 |
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. |
