Number of days available for climatic review
| Parameter | Jan | Feb | Mar | Apr | May | Jun |
| Tmax | 954 | 865 | 956 | 930 | 956 | 929 |
| Tmin | 950 | 864 | 949 | 923 | 947 | 917 |
| Duration of sunshine | 334 | 268 | 366 | 297 | 395 | 358 |
| Precipitation | 527 | 477 | 528 | 511 | 529 | 510 |
| Humidity/Visibility | 173 | 157 | 172 | 168 | 170 | 168 |
| Parameter | Jul | Aug | Sep | Oct | Nov | Dec |
| Tmax | 956 | 960 | 954 | 986 | 953 | 957 |
| Tmin | 942 | 952 | 950 | 983 | 953 | 964 |
| Duration of sunshine | 428 | 366 | 411 | 455 | 411 | 420 |
| Precipitation | 532 | 530 | 540 | 556 | 540 | 540 |
| Humidity/Visibility | 171 | 173 | 195 | 199 | 193 | 184 |
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. |
