Number of days available for climatic review
| Parameter | Jan | Feb | Mar | Apr | May | Jun |
| Tmax | 319 | 290 | 313 | 312 | 332 | 318 |
| Tmin | 320 | 282 | 307 | 315 | 329 | 318 |
| Duration of sunshine | 124 | 56 | 93 | 90 | 124 | 120 |
| Precipitation | 94 | 87 | 95 | 110 | 124 | 122 |
| Humidity/Visibility | 92 | 84 | 91 | 103 | 122 | 117 |
| Parameter | Jul | Aug | Sep | Oct | Nov | Dec |
| Tmax | 334 | 321 | 330 | 357 | 354 | 350 |
| Tmin | 336 | 326 | 327 | 355 | 355 | 356 |
| Duration of sunshine | 155 | 155 | 180 | 93 | 60 | 155 |
| Precipitation | 127 | 129 | 122 | 124 | 120 | 124 |
| Humidity/Visibility | 122 | 121 | 117 | 116 | 118 | 123 |
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. |
