Number of days available for climatic review
| Parameter | Jan | Feb | Mar | Apr | May | Jun |
| Tmax | 177 | 156 | 176 | 169 | 177 | 177 |
| Tmin | 145 | 142 | 163 | 156 | 164 | 145 |
| Duration of sunshine | 74 | 86 | 88 | 73 | 59 | 68 |
| Precipitation | 185 | 167 | 183 | 179 | 186 | 179 |
| Humidity/Visibility | 143 | 128 | 139 | 140 | 140 | 142 |
| Parameter | Jul | Aug | Sep | Oct | Nov | Dec |
| Tmax | 169 | 167 | 202 | 200 | 200 | 191 |
| Tmin | 151 | 146 | 189 | 194 | 201 | 169 |
| Duration of sunshine | 65 | 66 | 91 | 84 | 77 | 56 |
| Precipitation | 187 | 181 | 210 | 211 | 209 | 213 |
| Humidity/Visibility | 134 | 133 | 163 | 165 | 170 | 154 |
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. |
