Number of days available for climatic review
| Parameter | Jan | Feb | Mar | Apr | May | Jun |
| Tmax | 306 | 275 | 307 | 299 | 307 | 298 |
| Tmin | 306 | 278 | 310 | 298 | 308 | 299 |
| Duration of sunshine | 93 | 84 | 124 | 120 | 124 | 120 |
| Precipitation | 186 | 170 | 186 | 181 | 186 | 180 |
| Humidity/Visibility | 182 | 166 | 183 | 179 | 184 | 178 |
| Parameter | Jul | Aug | Sep | Oct | Nov | Dec |
| Tmax | 306 | 307 | 323 | 331 | 324 | 340 |
| Tmin | 308 | 310 | 328 | 331 | 328 | 340 |
| Duration of sunshine | 124 | 124 | 120 | 124 | 120 | 124 |
| Precipitation | 186 | 192 | 212 | 215 | 210 | 217 |
| Humidity/Visibility | 181 | 183 | 205 | 207 | 204 | 213 |
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. |
