Number of days available for climatic review
| Parameter | Jan | Feb | Mar | Apr | May | Jun |
| Tmax | 1164 | 1062 | 1169 | 1137 | 1169 | 1129 |
| Tmin | 1140 | 1038 | 1142 | 1109 | 1142 | 1104 |
| Duration of sunshine | 301 | 327 | 331 | 383 | 355 | 354 |
| Precipitation | 186 | 169 | 186 | 180 | 186 | 179 |
| Humidity/Visibility | 167 | 151 | 167 | 161 | 166 | 158 |
| Parameter | Jul | Aug | Sep | Oct | Nov | Dec |
| Tmax | 1167 | 1175 | 1161 | 1196 | 1165 | 1174 |
| Tmin | 1144 | 1143 | 1138 | 1173 | 1134 | 1176 |
| Duration of sunshine | 366 | 461 | 409 | 471 | 311 | 361 |
| Precipitation | 187 | 189 | 210 | 215 | 212 | 191 |
| Humidity/Visibility | 164 | 166 | 189 | 192 | 189 | 186 |
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. |
