Number of days available for climatic review
| Parameter | Jan | Feb | Mar | Apr | May | Jun |
| Tmax | 184 | 159 | 182 | 177 | 179 | 177 |
| Tmin | 183 | 165 | 180 | 174 | 174 | 176 |
| Duration of sunshine | 177 | 155 | 173 | 172 | 177 | 173 |
| Precipitation | 188 | 170 | 192 | 185 | 196 | 188 |
| Humidity/Visibility | 183 | 165 | 182 | 176 | 180 | 177 |
| Parameter | Jul | Aug | Sep | Oct | Nov | Dec |
| Tmax | 180 | 184 | 202 | 207 | 203 | 210 |
| Tmin | 180 | 179 | 201 | 203 | 200 | 205 |
| Duration of sunshine | 174 | 170 | 195 | 198 | 196 | 200 |
| Precipitation | 191 | 194 | 216 | 221 | 216 | 232 |
| Humidity/Visibility | 181 | 182 | 202 | 208 | 203 | 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. |
