Number of days available for climatic review
| Parameter | Jan | Feb | Mar | Apr | May | Jun |
| Tmax | 86 | 79 | 90 | 99 | 89 | 78 |
| Tmin | 86 | 84 | 86 | 92 | 98 | 91 |
| Duration of sunshine | 80 | 82 | 85 | 91 | 92 | 88 |
| Precipitation | 138 | 128 | 143 | 140 | 137 | 138 |
| Humidity/Visibility | 77 | 77 | 83 | 86 | 86 | 79 |
| Parameter | Jul | Aug | Sep | Oct | Nov | Dec |
| Tmax | 96 | 99 | 77 | 70 | 73 | 84 |
| Tmin | 89 | 93 | 84 | 86 | 89 | 83 |
| Duration of sunshine | 76 | 95 | 81 | 82 | 83 | 67 |
| Precipitation | 147 | 142 | 136 | 136 | 134 | 160 |
| Humidity/Visibility | 84 | 86 | 76 | 69 | 74 | 73 |
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. |
