Number of days available for climatic review
| Parameter | Jan | Feb | Mar | Apr | May | Jun |
| Tmax | 3520 | 3181 | 3516 | 3413 | 3509 | 3401 |
| Tmin | 3525 | 3186 | 3528 | 3414 | 3514 | 3410 |
| Duration of sunshine | 62 | 57 | 62 | 60 | 124 | 150 |
| Precipitation | 155 | 141 | 156 | 151 | 155 | 150 |
| Humidity/Visibility | 153 | 138 | 153 | 148 | 153 | 146 |
| Parameter | Jul | Aug | Sep | Oct | Nov | Dec |
| Tmax | 3516 | 3512 | 3402 | 3554 | 3444 | 3567 |
| Tmin | 3526 | 3521 | 3418 | 3555 | 3445 | 3572 |
| Duration of sunshine | 155 | 124 | 120 | 124 | 90 | 62 |
| Precipitation | 157 | 157 | 152 | 184 | 180 | 186 |
| Humidity/Visibility | 150 | 149 | 148 | 176 | 175 | 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. |
