Number of days available for climatic review
| Parameter | Jan | Feb | Mar | Apr | May | Jun |
| Tmax | 365 | 331 | 359 | 332 | 364 | 357 |
| Tmin | 370 | 330 | 370 | 353 | 369 | 358 |
| Duration of sunshine | 173 | 151 | 170 | 163 | 169 | 171 |
| Precipitation | 190 | 172 | 186 | 191 | 186 | 180 |
| Humidity/Visibility | 180 | 164 | 177 | 163 | 180 | 176 |
| Parameter | Jul | Aug | Sep | Oct | Nov | Dec |
| Tmax | 337 | 339 | 384 | 380 | 376 | 387 |
| Tmin | 369 | 371 | 381 | 393 | 381 | 393 |
| Duration of sunshine | 171 | 167 | 190 | 194 | 186 | 191 |
| Precipitation | 189 | 194 | 216 | 215 | 222 | 225 |
| Humidity/Visibility | 166 | 167 | 202 | 199 | 198 | 203 |
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. |
