Number of days available for climatic review
| Parameter | Jan | Feb | Mar | Apr | May | Jun |
| Tmax | 1527 | 1402 | 1550 | 1499 | 1540 | 1479 |
| Tmin | 1528 | 1401 | 1549 | 1499 | 1541 | 1478 |
| Duration of sunshine | 184 | 166 | 185 | 178 | 186 | 178 |
| Precipitation | 186 | 169 | 186 | 181 | 186 | 180 |
| Humidity/Visibility | 184 | 167 | 185 | 177 | 184 | 178 |
| Parameter | Jul | Aug | Sep | Oct | Nov | Dec |
| Tmax | 1544 | 1549 | 1519 | 1573 | 1526 | 1581 |
| Tmin | 1544 | 1552 | 1521 | 1575 | 1526 | 1581 |
| Duration of sunshine | 179 | 187 | 208 | 208 | 204 | 217 |
| Precipitation | 184 | 190 | 210 | 215 | 209 | 217 |
| Humidity/Visibility | 180 | 185 | 206 | 210 | 205 | 215 |
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. |
