Number of days available for climatic review
| Parameter | Jan | Feb | Mar | Apr | May | Jun |
| Tmax | 120 | 106 | 119 | 143 | 153 | 146 |
| Tmin | 123 | 109 | 121 | 138 | 152 | 145 |
| Duration of sunshine | 93 | 84 | 93 | 120 | 124 | 60 |
| Precipitation | 124 | 114 | 125 | 147 | 155 | 150 |
| Humidity/Visibility | 122 | 110 | 121 | 142 | 152 | 149 |
| Parameter | Jul | Aug | Sep | Oct | Nov | Dec |
| Tmax | 152 | 152 | 148 | 147 | 146 | 153 |
| Tmin | 149 | 153 | 148 | 140 | 145 | 150 |
| Duration of sunshine | 93 | 124 | 90 | 124 | 120 | 93 |
| Precipitation | 156 | 156 | 150 | 154 | 151 | 156 |
| Humidity/Visibility | 152 | 151 | 147 | 148 | 146 | 152 |
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. |
