Number of days available for climatic review
| Parameter | Jan | Feb | Mar | Apr | May | Jun |
| Tmax | 183 | 165 | 184 | 178 | 183 | 178 |
| Tmin | 183 | 165 | 185 | 177 | 185 | 174 |
| Duration of sunshine | 399 | 418 | 433 | 447 | 433 | 444 |
| Precipitation | 186 | 168 | 188 | 181 | 186 | 182 |
| Humidity/Visibility | 183 | 166 | 184 | 178 | 184 | 177 |
| Parameter | Jul | Aug | Sep | Oct | Nov | Dec |
| Tmax | 181 | 184 | 206 | 209 | 204 | 207 |
| Tmin | 181 | 187 | 206 | 207 | 204 | 208 |
| Duration of sunshine | 491 | 497 | 507 | 486 | 474 | 486 |
| Precipitation | 184 | 190 | 214 | 215 | 212 | 219 |
| Humidity/Visibility | 181 | 184 | 205 | 209 | 205 | 206 |
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. |
