Number of days available for climatic review
| Parameter | Jan | Feb | Mar | Apr | May | Jun |
| Tmax | 308 | 279 | 340 | 327 | 340 | 328 |
| Tmin | 309 | 278 | 337 | 325 | 339 | 326 |
| Duration of sunshine | 122 | 110 | 151 | 140 | 151 | 139 |
| Precipitation | 125 | 117 | 154 | 159 | 157 | 150 |
| Humidity/Visibility | 122 | 111 | 149 | 147 | 152 | 147 |
| Parameter | Jul | Aug | Sep | Oct | Nov | Dec |
| Tmax | 338 | 309 | 299 | 309 | 287 | 280 |
| Tmin | 337 | 311 | 298 | 307 | 287 | 280 |
| Duration of sunshine | 135 | 106 | 109 | 115 | 102 | 90 |
| Precipitation | 159 | 163 | 152 | 155 | 155 | 157 |
| Humidity/Visibility | 150 | 148 | 147 | 147 | 147 | 152 |
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. |
