Number of days available for climatic review
| Parameter | Jan | Feb | Mar | Apr | May | Jun |
| Tmax | 151 | 133 | 150 | 146 | 147 | 143 |
| Tmin | 145 | 137 | 149 | 147 | 150 | 149 |
| Duration of sunshine | 142 | 136 | 148 | 145 | 147 | 143 |
| Precipitation | 157 | 142 | 157 | 153 | 154 | 150 |
| Humidity/Visibility | 149 | 136 | 151 | 147 | 149 | 146 |
| Parameter | Jul | Aug | Sep | Oct | Nov | Dec |
| Tmax | 145 | 139 | 145 | 137 | 118 | 123 |
| Tmin | 143 | 141 | 144 | 135 | 113 | 123 |
| Duration of sunshine | 138 | 137 | 138 | 134 | 117 | 121 |
| Precipitation | 153 | 158 | 158 | 148 | 122 | 130 |
| Humidity/Visibility | 145 | 139 | 144 | 137 | 116 | 122 |
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. |
