Number of days available for climatic review
| Parameter | Jan | Feb | Mar | Apr | May | Jun |
| Tmax | 1249 | 1138 | 1259 | 1212 | 1256 | 1219 |
| Tmin | 1243 | 1142 | 1269 | 1217 | 1262 | 1219 |
| Duration of sunshine | 186 | 197 | 279 | 240 | 279 | 270 |
| Precipitation | 190 | 175 | 191 | 181 | 186 | 180 |
| Humidity/Visibility | 178 | 159 | 180 | 173 | 177 | 173 |
| Parameter | Jul | Aug | Sep | Oct | Nov | Dec |
| Tmax | 1258 | 1255 | 1240 | 1285 | 1238 | 1281 |
| Tmin | 1261 | 1255 | 1240 | 1287 | 1242 | 1283 |
| Duration of sunshine | 310 | 248 | 300 | 279 | 300 | 310 |
| Precipitation | 186 | 192 | 212 | 219 | 209 | 228 |
| Humidity/Visibility | 179 | 173 | 196 | 198 | 191 | 199 |
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. |
