Number of days available for climatic review
| Parameter | Jan | Feb | Mar | Apr | May | Jun |
| Tmax | 325 | 302 | 340 | 334 | 352 | 335 |
| Tmin | 291 | 273 | 310 | 302 | 307 | 295 |
| Duration of sunshine | 57 | 52 | 58 | 59 | 72 | 82 |
| Precipitation | 327 | 309 | 341 | 347 | 372 | 360 |
| Humidity/Visibility | 69 | 70 | 82 | 100 | 110 | 112 |
| Parameter | Jul | Aug | Sep | Oct | Nov | Dec |
| Tmax | 335 | 331 | 332 | 337 | 321 | 312 |
| Tmin | 306 | 301 | 303 | 305 | 291 | 280 |
| Duration of sunshine | 87 | 93 | 85 | 81 | 89 | 93 |
| Precipitation | 378 | 372 | 360 | 370 | 360 | 124 |
| Humidity/Visibility | 112 | 114 | 110 | 108 | 106 | 100 |
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. |
