Number of days available for climatic review
| Parameter | Jan | Feb | Mar | Apr | May | Jun |
| Tmax | 88 | 65 | 79 | 81 | 87 | 73 |
| Tmin | 101 | 79 | 86 | 83 | 90 | 82 |
| Duration of sunshine | 103 | 78 | 89 | 84 | 88 | 80 |
| Precipitation | 157 | 142 | 171 | 178 | 163 | 149 |
| Humidity/Visibility | 139 | 124 | 134 | 116 | 119 | 129 |
| Parameter | Jul | Aug | Sep | Oct | Nov | Dec |
| Tmax | 84 | 103 | 90 | 85 | 79 | 87 |
| Tmin | 86 | 104 | 88 | 82 | 73 | 85 |
| Duration of sunshine | 84 | 105 | 89 | 83 | 78 | 85 |
| Precipitation | 159 | 192 | 199 | 187 | 170 | 169 |
| Humidity/Visibility | 109 | 131 | 157 | 157 | 128 | 142 |
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. |
