Number of days available for climatic review
| Parameter | Jan | Feb | Mar | Apr | May | Jun |
| Tmax | 153 | 139 | 153 | 147 | 155 | 149 |
| Tmin | 154 | 138 | 154 | 149 | 155 | 149 |
| Duration of sunshine | 155 | 137 | 155 | 149 | 154 | 148 |
| Precipitation | 157 | 140 | 155 | 151 | 155 | 151 |
| Humidity/Visibility | 154 | 139 | 154 | 149 | 154 | 149 |
| Parameter | Jul | Aug | Sep | Oct | Nov | Dec |
| Tmax | 181 | 182 | 177 | 180 | 176 | 183 |
| Tmin | 183 | 186 | 177 | 179 | 179 | 180 |
| Duration of sunshine | 184 | 185 | 177 | 179 | 179 | 185 |
| Precipitation | 188 | 188 | 180 | 183 | 180 | 186 |
| Humidity/Visibility | 184 | 182 | 178 | 180 | 178 | 184 |
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. |
