Number of days available for climatic review
| Parameter | Jan | Feb | Mar | Apr | May | Jun |
| Tmax | 76 | 57 | 69 | 75 | 78 | 69 |
| Tmin | 76 | 65 | 78 | 79 | 80 | 79 |
| Duration of sunshine | 49 | 45 | 59 | 78 | 79 | 79 |
| Precipitation | 102 | 90 | 92 | 115 | 128 | 122 |
| Humidity/Visibility | 78 | 67 | 81 | 95 | 110 | 105 |
| Parameter | Jul | Aug | Sep | Oct | Nov | Dec |
| Tmax | 74 | 78 | 84 | 73 | 78 | 84 |
| Tmin | 74 | 72 | 83 | 76 | 79 | 87 |
| Duration of sunshine | 68 | 74 | 74 | 56 | 51 | 54 |
| Precipitation | 121 | 135 | 125 | 118 | 94 | 101 |
| Humidity/Visibility | 107 | 98 | 109 | 100 | 76 | 88 |
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. |
