Number of days available for climatic review
| Parameter | Jan | Feb | Mar | Apr | May | Jun |
| Tmax | 180 | 162 | 184 | 155 | 151 | 147 |
| Tmin | 179 | 158 | 181 | 155 | 145 | 144 |
| Duration of sunshine | 177 | 152 | 170 | 150 | 141 | 140 |
| Precipitation | 194 | 174 | 190 | 185 | 195 | 184 |
| Humidity/Visibility | 135 | 123 | 137 | 132 | 136 | 132 |
| Parameter | Jul | Aug | Sep | Oct | Nov | Dec |
| Tmax | 152 | 122 | 138 | 120 | 120 | 103 |
| Tmin | 152 | 127 | 133 | 117 | 119 | 105 |
| Duration of sunshine | 146 | 117 | 125 | 108 | 112 | 96 |
| Precipitation | 200 | 194 | 220 | 223 | 214 | 215 |
| Humidity/Visibility | 136 | 135 | 153 | 153 | 153 | 140 |
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. |
