Number of days available for climatic review
| Parameter | Jan | Feb | Mar | Apr | May | Jun |
| Tmax | 274 | 245 | 297 | 317 | 329 | 321 |
| Tmin | 277 | 247 | 301 | 316 | 338 | 327 |
| Duration of sunshine | 183 | 163 | 208 | 221 | 239 | 225 |
| Precipitation | 101 | 95 | 135 | 160 | 159 | 156 |
| Humidity/Visibility | 87 | 76 | 110 | 135 | 145 | 142 |
| Parameter | Jul | Aug | Sep | Oct | Nov | Dec |
| Tmax | 331 | 318 | 320 | 326 | 316 | 330 |
| Tmin | 336 | 333 | 326 | 330 | 326 | 338 |
| Duration of sunshine | 224 | 218 | 227 | 225 | 262 | 271 |
| Precipitation | 160 | 163 | 157 | 153 | 156 | 161 |
| Humidity/Visibility | 145 | 142 | 143 | 145 | 142 | 147 |
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. |
