Number of days available for climatic review
| Parameter | Jan | Feb | Mar | Apr | May | Jun |
| Tmax | 183 | 163 | 184 | 178 | 178 | 179 |
| Tmin | 183 | 166 | 185 | 178 | 181 | 174 |
| Duration of sunshine | 124 | 141 | 124 | 150 | 186 | 150 |
| Precipitation | 158 | 145 | 164 | 156 | 169 | 174 |
| Humidity/Visibility | 184 | 166 | 184 | 177 | 183 | 175 |
| Parameter | Jul | Aug | Sep | Oct | Nov | Dec |
| Tmax | 177 | 183 | 202 | 209 | 207 | 213 |
| Tmin | 181 | 181 | 206 | 207 | 206 | 215 |
| Duration of sunshine | 124 | 95 | 160 | 186 | 150 | 93 |
| Precipitation | 184 | 190 | 209 | 212 | 211 | 197 |
| Humidity/Visibility | 182 | 183 | 207 | 205 | 207 | 212 |
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. |
